### Question:
ExtensibleMetaDataMapping { public synchronized static ExtensibleMetaDataMapping instance(final Map<String, String> extensibleMappings) throws JargonException { log.debug("cacheing and returning fresh extensibleMetaDataMapping"); Map<String, String> copiedExtensibleMappings = new HashMap<String, String>(extensibleMappings); return new ExtensibleMetaDataMapping(Collections.unmodifiableMap(copiedExtensibleMappings)); } private  ExtensibleMetaDataMapping(final Map<String, String> extensibleMappings); synchronized static ExtensibleMetaDataMapping instance(final Map<String, String> extensibleMappings); String getIndexFromColumnName(final String columnName); String getColumnNameFromIndex(final String index);  }### Answer:
@Test public final void testInstance() throws Exception { Map<String, String> metaDataSource = new HashMap<String, String>(); String key1 = "key1"; String val1 = "10003"; String key2 = "key2"; String val2 = "10004"; metaDataSource.put(key1, val1); metaDataSource.put(key2, val2); ExtensibleMetaDataMapping metaDataMapping = ExtensibleMetaDataMapping.instance(metaDataSource); Assert.assertNotNull(metaDataMapping); }