@Override
  public void dropConstraint(String dbName, String tableName, String constraintName)
      throws TException {
    dropConstraint(getDefaultCatalog(conf), dbName, tableName, constraintName);
  }
@param request
@throws MetaException
@throws NoSuchObjectException
@throws TException
standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/HiveMetaStoreClient.java