### Question:
MetaDataAttributesElement extends ElementDefinition<String> { protected FeatureMap.Entry extensionOf(String metaData) { return new EStructuralFeatureImpl.SimpleFeatureMapEntry( (EStructuralFeature.Internal) DOCUMENT_ROOT__META_DATA, metaDataTypeDataOf(metaData)); } MetaDataAttributesElement(String name); @Override String getValue(BaseElement element); @Override void setValue(BaseElement element, String value); static final String DELIMITER; static final String SEPARATOR; }### Answer:
@Test public void testExtensionOf() { MetaDataAttributesElement metaDataAttributesElement = new MetaDataAttributesElement(NAME); MetaDataType metaDataType = metaDataAttributesElement.metaDataTypeDataOf(ATTRIBUTE); FeatureMap.Entry entry = metaDataAttributesElement.extensionOf(ATTRIBUTE); assertNotNull(entry); assertTrue(entry instanceof EStructuralFeatureImpl.SimpleFeatureMapEntry); assertEquals(DOCUMENT_ROOT__META_DATA, entry.getEStructuralFeature()); assertNotNull(entry.getValue()); assertEquals(metaDataType.getName(), ((MetaDataType) entry.getValue()).getName()); assertEquals(metaDataType.getMetaValue(), ((MetaDataType) entry.getValue()).getMetaValue()); }