message: Make sure that updating function defs to context can be successfully done when
  importing concrete function from manipulated graph def
  If not, it will encounter the duplicated function definitions errors.
diff: @@ -28,6 +28,7 @@ from tensorflow.core.framework import variable_pb2
  from tensorflow.core.protobuf import config_pb2
  from tensorflow.core.protobuf import meta_graph_pb2
  from tensorflow.core.protobuf import rewriter_config_pb2
  +from tensorflow.python.eager import context
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import graph_util
  from tensorflow.python.framework import ops
  @@ -998,6 +999,12 @@ def _construct_concrete_function(func, output_graph_def,
  new_input_names = [tensor.name for tensor in not_converted_inputs]
  new_output_names = [tensor.name for tensor in func.outputs]
  +
  + # Remove old functions to use updated functions from graph def.
  + for f in output_graph_def.library.function:
  + if context.context().has_function(f.signature.name):
  + context.context().remove_function(f.signature.name)
  +
  new_func = wrap_function.function_from_graph_def(output_graph_def,
  new_input_names,
  new_output_names)
  