### Question:
MetadataIdentificationUtils { public static boolean isValid(final String metadataIdentificationString) { if (metadataIdentificationString == null || metadataIdentificationString.length() <= MID_PREFIX_LENGTH) { return false; } for (int i = 0; i < MID_PREFIX_LENGTH; i++) { if (metadataIdentificationString.charAt(i) != MID_PREFIX_CHARACTERS[i]) { return false; } } return true; } 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 testClassMidIsValid() { assertTrue(MetadataIdentificationUtils.isValid(CLASS_MID)); }
@Test public void testEmptyMidIsNotValid() { assertFalse(MetadataIdentificationUtils.isValid("")); }
@Test public void testInstanceMidIsValid() { assertTrue(MetadataIdentificationUtils.isValid(CLASS_MID)); }
@Test public void testMidPrefixIsNotValid() { assertFalse(MetadataIdentificationUtils.isValid(MID_PREFIX)); }
@Test public void testNullMidIsNotValid() { assertFalse(MetadataIdentificationUtils.isValid(null)); }
@Test public void testUnprefixedMidIsNotValid() { assertFalse(MetadataIdentificationUtils.isValid(METADATA_CLASS)); }
@Test public void testBlankMidIsNotValid() { assertFalse(MetadataIdentificationUtils.isValid("\t\n\r")); }