### Question:
MetadataIdentificationUtils { public static String getMetadataInstance(final String metadataId) { if (isIdentifyingInstance(metadataId)) { return metadataId.substring(metadataId.indexOf(INSTANCE_DELIMITER) + 1); } return null; } private  MetadataIdentificationUtils(); static String create(final Class<?> metadataClass); static String create(final String fullyQualifiedClassName); static String create(final String fullyQualifiedMetadataClass,
      final String instanceIdentificationKey); static String getMetadataClass(final String metadataId); static String getMetadataClassId(final String metadataId); static String getMetadataInstance(final String metadataId); static boolean isIdentifyingClass(final String metadataIdentificationString); static boolean isIdentifyingInstance(final String metadataIdentificationString); static boolean isValid(final String metadataIdentificationString);  }### Answer:
@Test public void testGetInstanceKey() { assertEquals(INSTANCE_CLASS, MetadataIdentificationUtils.getMetadataInstance(INSTANCE_MID)); }
@Test public void testGetMetadataInstanceFromClassMid() { assertNull(MetadataIdentificationUtils.getMetadataInstance(CLASS_MID)); }
@Test public void testGetMetadataInstanceFromEmptyMid() { assertNull(MetadataIdentificationUtils.getMetadataInstance("")); }
@Test public void testGetMetadataInstanceFromInstanceMid() { assertEquals(INSTANCE_CLASS, MetadataIdentificationUtils.getMetadataInstance(INSTANCE_MID)); }
@Test public void testGetMetadataInstanceFromMidPrefix() { assertNull(MetadataIdentificationUtils.getMetadataInstance(MID_PREFIX)); }
@Test public void testGetMetadataInstanceFromMidPrefixPlusDelimiter() { assertNull(MetadataIdentificationUtils.getMetadataInstance(MID_PREFIX + INSTANCE_DELIMITER)); }
@Test public void testGetMetadataInstanceFromNullMid() { assertNull(MetadataIdentificationUtils.getMetadataInstance(null)); }