code: def StaticAdd(cls, queue_urn, rdf_value, mutation_pool=None):
      
      if not isinstance(rdf_value, cls.rdf_type):
        raise ValueError("This collection only accepts values of type %s." %
                         cls.rdf_type.__name__)
      if mutation_pool is None:
        raise ValueError("Mutation pool can't be none.")
  
      timestamp = rdfvalue.RDFDatetime.Now().AsMicrosecondsSinceEpoch()
  
      if not isinstance(queue_urn, rdfvalue.RDFURN):
        queue_urn = rdfvalue.RDFURN(queue_urn)
  
      mutation_pool.QueueAddItem(queue_urn, rdf_value, timestamp)
docs: Adds an rdf value the queue.
  
      Adds an rdf value to a queue. Does not require that the queue be locked, or
      even open. NOTE: The caller is responsible for ensuring that the queue
      exists and is of the correct type.
  
      Args:
        queue_urn: The urn of the queue to add to.
  
        rdf_value: The rdf value to add to the queue.
  
        mutation_pool: A MutationPool object to write to.
  
      Raises:
        ValueError: rdf_value has unexpected type.