def METHOD_NAME(self, branching_node_key: str):
    """
    De-registers any quantizers that were previously registered to be "waiting" on a given node key.
    :param branching_node_key: The node key in QuantizerPropagationStateGraph that some propagating
      quantizers have previously been registered upon.
    """
    for pq in self._branching_node_keys_vs_quantizers_waiting_for_merge[branching_node_key]:
        self._quantizers_vs_branching_node_keys.pop(pq)
    self._branching_node_keys_vs_quantizers_waiting_for_merge.pop(branching_node_key)