docstr: Create a copy of GraphDef.
docstr_tok: ["Create","a","copy","of","GraphDef","."]
code: def _copy_graph(self, graph_def):
      """Create a copy of GraphDef."""
      graph_def_copy = graph_pb2.GraphDef()
      graph_def_copy.CopyFrom(graph_def)
      return graph_def_copy
  
imports: import itertools
  from google.protobuf import message
  from google.protobuf import text_format
  from tensorflow.core.framework import function_pb2
  from tensorflow.core.framework import graph_pb2
  from tensorflow.python.platform import test
  from tensorflow.tools.proto_splitter import chunk_pb2
  from tensorflow.tools.proto_splitter import constants
  from tensorflow.tools.proto_splitter import split_graph_def
  from tensorflow.tools.proto_splitter import util
  from tensorflow.tools.proto_splitter.python import test_util
label_desc: Use image node_id 2 for calling the GraphDefSplitterTest obj's underlying member method code with example usage: obj._copy_graph(graph_def) and returns: graph_def_copy