Examples with DataDrivenValueConstant org.eclipse.tracecompass.internal.tmf.analysis.xml.core.fsm.model.values.DataDrivenValueConstant used on opensource projects

Example 1 with DataDrivenValueConstant

use of org.eclipse.tracecompass.internal.tmf.analysis.xml.core.fsm.model.values.DataDrivenValueConstant in project tracecompass by tracecompass.

the class TmfXmlStateAttributeAndLocationCuTest method testValidStateAttributeCompilation.

/**
 * Test the compilation of a valid state attribute strings, except locations
 *
 * @throws SAXException
 *             Exception thrown by parser
 * @throws IOException
 *             Exception thrown by parser
 * @throws ParserConfigurationException
 *             Exception thrown by parser
 */
@Test
public void testValidStateAttributeCompilation() throws SAXException, IOException, ParserConfigurationException {
    String[] validStrings = { "<stateAttribute type=\"null\" />", "<stateAttribute type=\"constant\" value=\"42\" />", "<stateAttribute type=\"eventField\" value=\"myfield\" />", "<stateAttribute type=\"eventName\" />", "<stateAttribute type=\"eventName\" value=\"ignored\" />", "<stateAttribute type=\"query\" ><stateAttribute type=\"constant\" value=\"queryPath\"/></stateAttribute>", "<stateAttribute type=\"self\" />", "<stateAttribute type=\"pool\" />" };
    DataDrivenValue[] generated = { TmfXmlTestUtils.NULL_VALUE, new DataDrivenValueConstant(null, ITmfStateValue.Type.NULL, "42"), new DataDrivenValueEventField(null, ITmfStateValue.Type.NULL, "myfield"), new DataDrivenValueEventName(null), new DataDrivenValueEventName(null), new DataDrivenValueQuery(null, ITmfStateValue.Type.NULL, new DataDrivenStateSystemPath(ImmutableList.of(new DataDrivenValueConstant(null, ITmfStateValue.Type.NULL, "queryPath")), IBaseQuarkProvider.IDENTITY_BASE_QUARK)), new DataDrivenValueSelf(ITmfStateValue.Type.NULL), DataDrivenValuePool.getInstance() };
    for (int i = 0; i < validStrings.length; i++) {
        String validString = validStrings[i];
        DataDrivenValue runtimeObj = generated[i];
        Element xmlElement = TmfXmlTestUtils.getXmlElement(TmfXmlStrings.STATE_ATTRIBUTE, validString);
        assertNotNull(xmlElement);
        List<@NonNull TmfXmlStateValueCu> compileAttribute = TmfXmlStateValueCu.compileAttribute(ANALYSIS_DATA, xmlElement);
        assertNotNull(validString, compileAttribute);
        assertEquals("Number of attributes", 1, compileAttribute.size());
        TmfXmlStateValueCu value = compileAttribute.get(0);
        assertEquals("Expected attribute", runtimeObj, value.generate());
    }
}

Example 2 with DataDrivenValueConstant

use of org.eclipse.tracecompass.internal.tmf.analysis.xml.core.fsm.model.values.DataDrivenValueConstant in project tracecompass by tracecompass.

the class TmfXmlActionCu method compileSegmentAction.

@Nullable
private static TmfXmlActionCu compileSegmentAction(AnalysisCompilationData analysisData, Element node) {
    // Compile the segment type
    List<@NonNull Element> segmentType = TmfXmlUtils.getChildElements(node, TmfXmlStrings.SEGMENT_TYPE);
    if (segmentType.size() != 1) {
        // TODO: Validation message here
        // $NON-NLS-1$ //$NON-NLS-2$
        Activator.logWarning("Segment action: There should be one and only one " + TmfXmlStrings.SEGMENT_TYPE + " element.");
        return null;
    }
    Element typeElement = Objects.requireNonNull(segmentType.get(0));
    String segmentName = typeElement.getAttribute(TmfXmlStrings.SEGMENT_NAME);
    TmfXmlStateValueCu segmentTypeValue = null;
    if (!segmentName.isEmpty()) {
        // Constant name for the segment type
        segmentTypeValue = new TmfXmlStateValueCu(() -> new DataDrivenValueConstant(null, ITmfStateValue.Type.NULL, segmentName));
    } else {
        List<Element> nameElements = TmfXmlUtils.getChildElements(typeElement, TmfXmlStrings.SEGMENT_NAME);
        if (nameElements.size() != 1) {
            // TODO: Validation message here
            // $NON-NLS-1$
            Activator.logError("Segment type: You need to either give a segName attribute or define one and only one <segName> element with child <stateValue> to get the type name");
            return null;
        }
        Element segNameElement = Objects.requireNonNull(nameElements.get(0));
        List<Element> nameValueElements = TmfXmlUtils.getChildElements(segNameElement, TmfXmlStrings.STATE_VALUE);
        if (nameValueElements.size() != 1) {
            // TODO: Validation message here
            // $NON-NLS-1$
            Activator.logError("Segment type: the <segName> element should have one and only one <stateValue> child");
            return null;
        }
        Element segNameValueElement = Objects.requireNonNull(nameValueElements.get(0));
        segmentTypeValue = TmfXmlStateValueCu.compileValue(analysisData, segNameValueElement);
    }
    if (segmentTypeValue == null) {
        return null;
    }
    // Compile the optional time element
    TmfXmlStateValueCu beginTimeValue = null;
    TmfXmlStateValueCu durationValue = null;
    TmfXmlStateValueCu endTimeValue = null;
    List<Element> timeElements = TmfXmlUtils.getChildElements(node, TmfXmlStrings.SEGMENT_TIME);
    if (timeElements.size() > 1) {
        // TODO: Validation message here
        // $NON-NLS-1$
        Activator.logWarning("Segment time: there should be only one <segTime> element");
    }
    if (timeElements.size() > 0) {
        Element segTimeElement = Objects.requireNonNull(timeElements.get(0));
        List<Element> beginElements = TmfXmlUtils.getChildElements(segTimeElement, TmfXmlStrings.BEGIN);
        if (beginElements.isEmpty()) {
            // TODO: Validation message here
            // $NON-NLS-1$
            Activator.logError("Segment time: there should be one <begin> element to describe segment start time");
            return null;
        }
        if (beginElements.size() > 1) {
            // TODO: Validation message here
            // $NON-NLS-1$
            Activator.logWarning("Segment time: there should be only one <begin> element");
        }
        beginTimeValue = TmfXmlStateValueCu.compileValue(analysisData, Objects.requireNonNull(beginElements.get(0)));
        if (beginTimeValue == null) {
            return null;
        }
        beginTimeValue = new TmfXmlStateValueCu(new TmfXmlStateValueCu.ValueWrapperGenerator(beginTimeValue, ITmfStateValue.Type.LONG));
        // Validate end time or duration
        List<Element> durationElements = TmfXmlUtils.getChildElements(segTimeElement, TmfXmlStrings.DURATION);
        List<Element> endElements = TmfXmlUtils.getChildElements(segTimeElement, TmfXmlStrings.END);
        if (durationElements.isEmpty() && endElements.isEmpty()) {
            // TODO: Validation message here
            // $NON-NLS-1$
            Activator.logError("Segment time: there should be either a <duration> or <end> element");
            return null;
        }
        if (!durationElements.isEmpty() && !endElements.isEmpty()) {
            // TODO: Validation message here
            // $NON-NLS-1$
            Activator.logError("Segment time: only one of <duration> or <end> shoud be present");
            return null;
        }
        if (durationElements.size() > 1) {
            // TODO: Validation message here
            // $NON-NLS-1$
            Activator.logWarning("Segment time: there should be only one <duration> element");
        }
        if (endElements.size() > 1) {
            // TODO: Validation message here
            // $NON-NLS-1$
            Activator.logWarning("Segment time: there should be only one <end> element");
        }
        if (!durationElements.isEmpty()) {
            durationValue = TmfXmlStateValueCu.compileValue(analysisData, Objects.requireNonNull(durationElements.get(0)));
            if (durationValue == null) {
                return null;
            }
            durationValue = new TmfXmlStateValueCu(new TmfXmlStateValueCu.ValueWrapperGenerator(durationValue, ITmfStateValue.Type.LONG));
        } else {
            endTimeValue = TmfXmlStateValueCu.compileValue(analysisData, Objects.requireNonNull(endElements.get(0)));
            if (endTimeValue == null) {
                return null;
            }
            endTimeValue = new TmfXmlStateValueCu(new TmfXmlStateValueCu.ValueWrapperGenerator(endTimeValue, ITmfStateValue.Type.LONG));
        }
    }
    // Compile the segment fields
    List<Element> contentElements = TmfXmlUtils.getChildElements(node, TmfXmlStrings.SEGMENT_CONTENT);
    Map<String, TmfXmlStateValueCu> fieldMap = new HashMap<>();
    for (Element contentEl : contentElements) {
        List<Element> fieldElements = TmfXmlUtils.getChildElements(contentEl, TmfXmlStrings.SEGMENT_FIELD);
        for (Element fieldEl : fieldElements) {
            String name = fieldEl.getAttribute(TmfXmlStrings.NAME);
            if (name.isEmpty()) {
                // TODO: Validation message here
                // $NON-NLS-1$
                Activator.logError("Segment field does not have a name");
                return null;
            }
            if (fieldMap.containsKey(name)) {
                // TODO: Validation message here
                // $NON-NLS-1$
                Activator.logError("Redefinition of field " + name);
                return null;
            }
            TmfXmlStateValueCu fieldCu = TmfXmlStateValueCu.compileSegmentField(analysisData, fieldEl);
            if (fieldCu == null) {
                return null;
            }
            fieldMap.put(name, fieldCu);
        }
    }
    return new TmfXmlActionSegmentCu(segmentTypeValue, beginTimeValue, durationValue, endTimeValue, fieldMap);
}

Example 3 with DataDrivenValueConstant

use of org.eclipse.tracecompass.internal.tmf.analysis.xml.core.fsm.model.values.DataDrivenValueConstant in project tracecompass by tracecompass.

the class TmfXmlStateValueCu method compileAttribute.

/**
 * Compile a stateAttribute XML element. It returns a list since some
 * attributes may link to location values that are replaced by the
 * corresponding attribute values.
 *
 * @param analysisData
 *            The analysis data already compiled
 * @param valueEl
 *            The XML element to compile
 * @return A list of value compilation units this element compiles to, or
 *         <code>null</code> if there was a compilation error
 */
@Nullable
public static List<TmfXmlStateValueCu> compileAttribute(AnalysisCompilationData analysisData, Element valueEl) {
    String type = valueEl.getAttribute(TmfXmlStrings.TYPE);
    Type forcedType = ITmfStateValue.Type.NULL;
    switch(type) {
        case TmfXmlStrings.TYPE_CONSTANT:
            {
                String name = getValueString(analysisData, valueEl);
                if (name == null || name.isEmpty()) {
                    // TODO: Validation message here
                    // $NON-NLS-1$
                    Activator.logError("The value of a constant attribute should not be empty");
                    return null;
                }
                if (name.equals(CURRENT_SCENARIO)) {
                    return Collections.singletonList(CURRENT_SCENARIO_QUARK);
                }
                TmfXmlStateValueCu tmfXmlStateValueCu = new TmfXmlStateValueCu(() -> new DataDrivenValueConstant(null, forcedType, name));
                return Collections.singletonList(tmfXmlStateValueCu);
            }
        case TmfXmlStrings.EVENT_FIELD:
            {
                String name = getValueString(analysisData, valueEl);
                if (name == null || name.isEmpty()) {
                    // TODO: Validation message here
                    // $NON-NLS-1$
                    Activator.logError("The value of an event field attribute should not be null");
                    return null;
                }
                return Collections.singletonList(new TmfXmlStateValueCu(() -> new DataDrivenValueEventField(null, forcedType, name)));
            }
        case TmfXmlStrings.TYPE_LOCATION:
            {
                String name = getValueString(analysisData, valueEl);
                if (name == null || name.isEmpty()) {
                    // TODO: Validation message here
                    // $NON-NLS-1$
                    Activator.logError("The value of a location attribute should not be null");
                    return null;
                }
                TmfXmlLocationCu location = analysisData.getLocation(name);
                if (location == null) {
                    // TODO: Validation message here
                    // $NON-NLS-1$ //$NON-NLS-2$
                    Activator.logError("Location " + name + " does not exist");
                    return null;
                }
                return location.getValues();
            }
        case TmfXmlStrings.TYPE_QUERY:
            {
                List<Element> childElements = TmfXmlUtils.getChildElements(valueEl, TmfXmlStrings.STATE_ATTRIBUTE);
                if (childElements.isEmpty()) {
                    // TODO: Validation message here
                    // $NON-NLS-1$
                    Activator.logError("A query state attribute should have children attributes");
                    return null;
                }
                TmfXmlStateSystemPathCu path = TmfXmlStateSystemPathCu.compile(analysisData, childElements);
                if (path == null) {
                    return null;
                }
                return Collections.singletonList(new TmfXmlStateValueCu(new StateValueQueryGenerator(path, null, forcedType)));
            }
        case TmfXmlStrings.TYPE_EVENT_NAME:
            return Collections.singletonList(new TmfXmlStateValueCu(() -> new DataDrivenValueEventName(null)));
        case TmfXmlStrings.TYPE_NULL:
            return Collections.singletonList(new TmfXmlStateValueCu(() -> new DataDrivenValueConstant(null, forcedType, null)));
        case TmfXmlStrings.TYPE_SELF:
            return Collections.singletonList(new TmfXmlStateValueCu(() -> new DataDrivenValueSelf(forcedType)));
        case TmfXmlStrings.TYPE_POOL:
            return Collections.singletonList(new TmfXmlStateValueCu(() -> DataDrivenValuePool.getInstance()));
        default:
            // $NON-NLS-1$
            Activator.logError("Compiling state value: The XML element is not of the right type " + type);
    }
    return null;
}

Example 4 with DataDrivenValueConstant

use of org.eclipse.tracecompass.internal.tmf.analysis.xml.core.fsm.model.values.DataDrivenValueConstant in project tracecompass by tracecompass.

the class TmfXmlStateValueCu method compileSegmentField.

/**
 * Compile a segment field element into a state value
 *
 * @param analysisData
 *            The analysis data already compiled
 * @param element
 *            The XML element to compile
 * @return The state value compilation unit
 */
@Nullable
public static TmfXmlStateValueCu compileSegmentField(AnalysisCompilationData analysisData, Element element) {
    String typeStr = element.getAttribute(TmfXmlStrings.TYPE);
    String name = element.getAttribute(TmfXmlStrings.NAME);
    if (typeStr.isEmpty()) {
        // TODO: Validation message here
        // $NON-NLS-1$
        Activator.logError("Segment field: missing 'type' attribute for field " + name);
        return null;
    }
    ITmfStateValue.Type type = TmfXmlUtils.getTmfStateValueByName(typeStr);
    if (type == null) {
        // TODO: Validation message here
        Activator.logError(// $NON-NLS-1$
        "The given type name \"" + typeStr + // $NON-NLS-1$
        "\" does not correspond to any ITmfStateValue.Type");
        return null;
    }
    String constantValue = getValueString(analysisData, element);
    List<Element> childElements = TmfXmlUtils.getChildElements(element, TmfXmlStrings.STATE_VALUE);
    if (type.equals(Type.NULL)) {
        if (constantValue != null && !constantValue.isEmpty()) {
            // TODO: Validation message here
            // $NON-NLS-1$
            Activator.logWarning("Segment field: type is null, the constant value will be ignored");
        }
        if (!childElements.isEmpty()) {
            // TODO: Validation message here
            // $NON-NLS-1$
            Activator.logWarning("Segment field: type is null, the <stateValue> element will be ignored");
        }
        return new TmfXmlStateValueCu(() -> new DataDrivenValueConstant(null, type, null));
    }
    if (constantValue == null || constantValue.isEmpty()) {
        // No constant field, look at the state value element
        if (childElements.isEmpty()) {
            // TODO: Validation message here
            // $NON-NLS-1$
            Activator.logError("Segment field: there should be either a 'value' attribute or <stateValue> element for type " + typeStr);
            return null;
        }
        if (childElements.size() > 1) {
            // TODO: Validation message here
            // $NON-NLS-1$
            Activator.logWarning("Segment field: there should be only one <stateValue> element under the field");
        }
        TmfXmlStateValueCu valueCu = compileValue(analysisData, Objects.requireNonNull(childElements.get(0)));
        if (valueCu == null) {
            return null;
        }
        return new TmfXmlStateValueCu(new ValueWrapperGenerator(valueCu, type));
    }
    // Create a constant state value with forced type
    if (!childElements.isEmpty()) {
        // TODO: Validation message here
        // $NON-NLS-1$
        Activator.logWarning("Segment field: type is null, the <stateValue> element will be ignored");
    }
    Object value = convertValueToType(constantValue, type);
    if (value == null) {
        return null;
    }
    return new TmfXmlStateValueCu(() -> new DataDrivenValueConstant(null, type, value));
}

Example 5 with DataDrivenValueConstant

use of org.eclipse.tracecompass.internal.tmf.analysis.xml.core.fsm.model.values.DataDrivenValueConstant in project tracecompass by tracecompass.

the class TmfXmlStateValueCu method compileValue.

/**
 * Compile a stateValue XML element
 *
 * @param analysisData
 *            The analysis data already compiled
 * @param valueEl
 *            The XML element to compile
 * @return The value compilation unit or <code>null</code> if there were
 *         compilation errors
 */
@Nullable
public static TmfXmlStateValueCu compileValue(AnalysisCompilationData analysisData, Element valueEl) {
    String type = valueEl.getAttribute(TmfXmlStrings.TYPE);
    /*
         * Stack peek will have a separate treatment here, as the state value
         * may have sub attributes
         *
         * FIXME: This case should not be supported this way, have a special
         * type for stack peek and remove the peek stack action..
         */
    String stack = valueEl.getAttribute(TmfXmlStrings.ATTRIBUTE_STACK);
    StackAction stackAction = DataDrivenActionStateChange.StackAction.getTypeFromString(stack);
    if (stackAction == StackAction.PEEK) {
        type = TmfXmlStrings.STACK_PEEK;
    }
    // Verify mapping group data
    String mapGroupAttrib = valueEl.getAttribute(TmfXmlStrings.MAPPING_GROUP);
    TmfXmlMappingGroupCu mappingGroup = analysisData.getMappingGroup(mapGroupAttrib);
    // Make sure the mapping group exists
    if (!mapGroupAttrib.isEmpty() && mappingGroup == null) {
        // TODO: Validation message here
        // $NON-NLS-1$ //$NON-NLS-2$
        Activator.logError("The mapping group " + mapGroupAttrib + " does not exist in this analysis");
        return null;
    }
    String mappingGroupId = (mapGroupAttrib.isEmpty() ? null : mapGroupAttrib);
    /*
         * Forced type allows to convert the value to a certain type : For
         * example, a process's TID in an event field may arrive with a LONG
         * format but we want to store the data in an INT
         */
    String forcedTypeName = valueEl.getAttribute(TmfXmlStrings.FORCED_TYPE);
    ITmfStateValue.Type forcedType = forcedTypeName.isEmpty() ? ITmfStateValue.Type.NULL : TmfXmlUtils.getTmfStateValueByName(forcedTypeName);
    if (forcedType == null) {
        // TODO: Validation message here
        Activator.logError(// $NON-NLS-1$
        "The given type name \"" + forcedType + // $NON-NLS-1$
        "\" does not correspond to any ITmfStateValue.Type");
        return null;
    }
    switch(type) {
        case TmfXmlStrings.TYPE_INT:
            {
                if (mappingGroup != null) {
                    // TODO: Validation message here
                    // $NON-NLS-1$
                    Activator.logWarning("state value is type int but a mappingGroup is specified");
                }
                String value = getValueString(analysisData, valueEl);
                if (value == null) {
                    return null;
                }
                Object intValue = convertValueToType(value, Type.INTEGER);
                if (intValue == null) {
                    return null;
                }
                return new TmfXmlStateValueCu(() -> new DataDrivenValueConstant(mappingGroupId, forcedType, intValue));
            }
        case TmfXmlStrings.TYPE_LONG:
            {
                if (mappingGroup != null) {
                    // TODO: Validation message here
                    // $NON-NLS-1$
                    Activator.logWarning("state value is type long but a mappingGroup is specified");
                }
                String value = getValueString(analysisData, valueEl);
                if (value == null) {
                    return null;
                }
                Object longValue = convertValueToType(value, Type.LONG);
                if (longValue == null) {
                    return null;
                }
                return new TmfXmlStateValueCu(() -> new DataDrivenValueConstant(mappingGroupId, forcedType, longValue));
            }
        case TmfXmlStrings.TYPE_STRING:
            {
                String value = getValueString(analysisData, valueEl);
                return new TmfXmlStateValueCu(() -> new DataDrivenValueConstant(mappingGroupId, forcedType, value));
            }
        case TmfXmlStrings.TYPE_NULL:
            {
                if (mappingGroup != null) {
                    // TODO: Validation message here
                    // $NON-NLS-1$
                    Activator.logWarning("state value is type null but a mappingGroup is specified");
                }
                return new TmfXmlStateValueCu(() -> new DataDrivenValueConstant(mappingGroupId, forcedType, null));
            }
        case TmfXmlStrings.EVENT_FIELD:
            {
                String name = getValueString(analysisData, valueEl);
                if (name == null || name.isEmpty()) {
                    // TODO: Validation message here
                    // $NON-NLS-1$
                    Activator.logError("The value of an event field attribute should not be null");
                    return null;
                }
                return new TmfXmlStateValueCu(() -> new DataDrivenValueEventField(mappingGroupId, forcedType, name));
            }
        case TmfXmlStrings.TYPE_EVENT_NAME:
            return new TmfXmlStateValueCu(() -> new DataDrivenValueEventName(mappingGroupId));
        case TmfXmlStrings.TYPE_DELETE:
            {
                if (mappingGroup != null) {
                    // TODO: Validation message here
                    // $NON-NLS-1$
                    Activator.logWarning("state value is type delete but a mappingGroup is specified");
                }
                return new TmfXmlStateValueCu(() -> new DataDrivenValueConstant(mappingGroupId, forcedType, null));
            }
        case TmfXmlStrings.TYPE_QUERY:
            {
                List<Element> childElements = TmfXmlUtils.getChildElements(valueEl, TmfXmlStrings.STATE_ATTRIBUTE);
                if (childElements.isEmpty()) {
                    // TODO: Validation message here
                    // $NON-NLS-1$
                    Activator.logError("A query state value should have children attributes");
                    return null;
                }
                TmfXmlStateSystemPathCu path = TmfXmlStateSystemPathCu.compile(analysisData, childElements);
                if (path == null) {
                    return null;
                }
                return new TmfXmlStateValueCu(new StateValueQueryGenerator(path, mappingGroupId, forcedType));
            }
        case TmfXmlStrings.TYPE_SCRIPT:
            {
                List<Element> childElements = TmfXmlUtils.getChildElements(valueEl, TmfXmlStrings.STATE_VALUE);
                Map<String, TmfXmlStateValueCu> values = new HashMap<>();
                for (Element subAttributeNode : childElements) {
                    // state values in a script should have an ID
                    String valueId = subAttributeNode.getAttribute(TmfXmlStrings.ID);
                    TmfXmlStateValueCu subAttrib = TmfXmlStateValueCu.compileValue(analysisData, subAttributeNode);
                    if (subAttrib == null) {
                        return null;
                    }
                    values.put(valueId, subAttrib);
                }
                String script = getValueString(analysisData, valueEl);
                if (script == null) {
                    // TODO: Validation message here
                    // $NON-NLS-1$
                    Activator.logError("The script resolves to null");
                    return null;
                }
                String scriptEngine = valueEl.getAttribute(TmfXmlStrings.SCRIPT_ENGINE);
                if (scriptEngine.isEmpty()) {
                    scriptEngine = DataDrivenValueScript.DEFAULT_SCRIPT_ENGINE;
                }
                return new TmfXmlStateValueCu(new StateValueScriptGenerator(values, script, scriptEngine, mappingGroupId, forcedType));
            }
        case TmfXmlStrings.STACK_PEEK:
            {
                // A stack peek is like a query at the top of the stack
                List<Element> childElements = TmfXmlUtils.getChildElements(valueEl, TmfXmlStrings.STATE_ATTRIBUTE);
                if (childElements.isEmpty()) {
                    // TODO: Validation message here
                    // $NON-NLS-1$
                    Activator.logWarning("Compiling state value: Stack peek should have children state attributes");
                }
                TmfXmlStateSystemPathCu path = TmfXmlStateSystemPathCu.compile(analysisData, childElements);
                if (path == null) {
                    return null;
                }
                return new TmfXmlStateValueCu(new StateValueStackPeekGenerator(path, mappingGroupId, forcedType));
            }
        default:
            // $NON-NLS-1$
            Activator.logError("Compiling state value: The XML element is not of the right type " + type);
    }
    return null;
}