code: void writeEntryId(Object entity) throws XMLStreamException, ODataEdmException {
  
          xmlWriter.writeStartElement(ATOM_ID);
          xmlWriter.writeCharacters(getEntryIdString(entity));
          xmlWriter.writeEndElement();
      }
docs: Write an {@code <id>} element when the parent element is an {@code <entry>} element.
  
  @param entity The entity to be contained by the {@code <entry>} element.
  @throws XMLStreamException If unable to write to stream
  @throws ODataEdmException  If unable to write entry to stream