code: def _check_valid_keys(keys):
      if any([x in keys for x in [EDGES, RECEIVERS, SENDERS]]):
          if not (RECEIVERS in keys and SENDERS in keys):
              raise ValueError(
                  "If edges are present, senders and receivers should "
                  "both be defined."
              )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  from graph_nets import graphs
  import networkx
  import numpy
  from six.moves import range
  from six.moves import zip
label_desc: Use image node_id 1 for calling a global function with example usage: _check_valid_keys(keys) without return types