code: def _GetClientIdFromQueue(q):
    
    split = q.Split()
    if not split or len(split) < 2:
      return None
  
    # Normalize to lowercase.
    split = [s.lower() for s in split]
  
    str_client_id, tasks_marker = split
  
    if not str_client_id.startswith("c.") or tasks_marker != "tasks":
      return None
  
    # The "C." prefix should be uppercase.
    str_client_id = "C" + str_client_id[1:]
  
    return str_client_id
docs: Returns q's client id, if q is a client task queue, otherwise None.
  
    Args:
      q: rdfvalue.RDFURN
  
    Returns:
      string or None