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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _GetClientIdFromQueue(q):
 """Returns q's client id, if q is a client task queue, otherwise None. Args: q: rdfvalue.RDFURN Returns: string or None """

  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