code: def set_zero_edge_features(
      graph, edge_size, dtype=tf.float32, name="set_zero_edge_features"
  ):
      """Completes the edge state of a graph.
  
      Args:
        graph: A `graphs.GraphsTuple` with a `None` edge state.
        edge_size: (int) the dimension for the created edge features.
        dtype: (tensorflow type) the type for the created edge features.
        name: (string, optional) A name for the operation.
  
      Returns:
        The same graph but for the edge field, which is a `Tensor` of shape
        `[number_of_edges, edge_size]`, where `number_of_edges = sum(graph.n_edge)`,
        with type `dtype` and filled with zeros.
  
      Raises:
        ValueError: If the `EDGES` field is not None in `graph`.
        ValueError: If the `RECEIVERS` or `SENDERS` field are None in `graph`.
        ValueError: If `edge_size` is None.
      """
      if graph.edges is not None:
          raise ValueError(
              "Cannot complete edge state if the graph already has edge features."
          )
      if graph.receivers is None or graph.senders is None:
          raise ValueError(
              "Cannot complete edge state if the receivers or senders are None."
          )
      if edge_size is None:
          raise ValueError("Cannot complete edges with None edge_size")
      with tf.name_scope(name):
          senders_leading_size = graph.senders.shape.as_list()[0]
          if senders_leading_size is not None:
              n_edges = senders_leading_size
          else:
              n_edges = tf.reduce_sum(graph.n_edge)
          return graph._replace(
              edges=tf.zeros(shape=[n_edges, edge_size], dtype=dtype)
          )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  import functools
  from absl import logging
  from graph_nets import graphs
  from graph_nets import utils_np
  import six
  from six.moves import range
  import tensorflow
  import tree
label_desc: Use image node_id 23 for calling a global function with example usage: set_zero_edge_features(graph, edge_size, dtype, name) and returns: graph