message: Replace is by ==
diff: @@ -275,25 +275,25 @@ def make_attribute(
  def get_attribute_value(attr): # type: (AttributeProto) -> Any
  - if attr.type is AttributeProto.FLOAT:
  + if attr.type == AttributeProto.FLOAT:
  return attr.f
  - elif attr.type is AttributeProto.INT:
  + elif attr.type == AttributeProto.INT:
  return attr.i
  - elif attr.type is AttributeProto.STRING:
  + elif attr.type == AttributeProto.STRING:
  return attr.s
  - elif attr.type is AttributeProto.TENSOR:
  + elif attr.type == AttributeProto.TENSOR:
  return attr.t
  - elif attr.type is AttributeProto.GRAPH:
  + elif attr.type == AttributeProto.GRAPH:
  return attr.g
  - elif attr.type is AttributeProto.FLOATS:
  + elif attr.type == AttributeProto.FLOATS:
  return list(attr.floats)
  - elif attr.type is AttributeProto.INTS:
  + elif attr.type == AttributeProto.INTS:
  return list(attr.ints)
  - elif attr.type is AttributeProto.STRINGS:
  + elif attr.type == AttributeProto.STRINGS:
  return list(attr.strings)
  - elif attr.type is AttributeProto.TENSORS:
  + elif attr.type == AttributeProto.TENSORS:
  return list(attr.tensors)
  - elif attr.type is AttributeProto.GRAPHS:
  + elif attr.type == AttributeProto.GRAPHS:
  return list(attr.graphs)
  else:
  raise ValueError("Unsupported ONNX attribute: {}".format(attr))
  