code: public static String getActualTableName(final OutputWriter outputWriter) {
          assert outputWriter instanceof DatastoreOutputWriter;
          final DatastoreOutputWriter dow = (DatastoreOutputWriter) outputWriter;
          return dow.getTableName();
      }
docs: Gets the actual table name written by an {@link OutputWriter}, which may
  differ from the requested name if the name was not a valid RDBMS table
  name or if the table name was already used and truncation was disabled.
  
  @param outputWriter
  @return