docs: def add_to_replication_queue(source_node_urn, sysmeta_pyxb):
      """Add a replication request issued by a CN to a queue that is processed
      asynchronously.
  
      Preconditions:
      - sysmeta_pyxb.identifier is verified to be available for create. E.g., with
        d1_gmn.app.views.is_valid_pid_for_create(pid).
  
      Postconditions:
      - The database is set up to track a new replica, with initial status, "queued".
      - The PID provided in the sysmeta_pyxb is reserved for the replica.
  
      """
      replica_info_model = d1_gmn.app.models.replica_info(
          status_str='queued', source_node_urn=source_node_urn
      )
      local_replica_model = d1_gmn.app.models.local_replica(
          pid=d1_common.xml.get_req_val(sysmeta_pyxb.identifier),
          replica_info_model=replica_info_model,
      )
      d1_gmn.app.models.replication_queue(
          local_replica_model=local_replica_model, size=sysmeta_pyxb.size
      )