for func in graph_def.library.function:
    for var_node in filter(_is_variable, func.node_def):
      variable_nodes[shared_name] = var_node

  return variable_nodes


class MultipleSignatureModel(module.Module):
  """A model with 2 signatures.

  Used to test where the quantizer has to handle multiple signatures.
  """

  def __init__(self):
    self.matmul_filters = random_ops.random_uniform(