def GenerateId(self, entity_id=None):
    """Generate a unique id based on the given id.

    This is done by appending a counter which is then incremented. The
    counter is initialised at the maximum number used as an ending for
    any id in the old and new schedules.

    Args:
      entity_id: The base id string. This is allowed to be None.

    Returns:
      The generated id.
    """
    self._idnum += 1
    if entity_id:
      return '%s_merged_%d' % (entity_id, self._idnum)
    else:
      return 'merged_%d' % self._idnum
Generate a unique id based on the given id.

    This is done by appending a counter which is then incremented. The
    counter is initialised at the maximum number used as an ending for
    any id in the old and new schedules.

    Args:
      entity_id: The base id string. This is allowed to be None.

    Returns:
      The generated id.