Args:
      func: A FunctionDef object.

    Returns:
      True iff `func` is quantized.
    """
    return func.signature.name.startswith('quantized_')

  def _is_composite_function(self, func: function_pb2.FunctionDef) -> bool:
    """Determine whether a FunctionDef is composite function.

    Args:
      func: A FunctionDef object.

    Returns: