message: >Tensor conversion function is now expected to only raise {Type,Value}Error
  The precise contract for conversion functions is currently undocumented, but
  the implementation additionally allowed errors.UnimplementedError and
  errors.InvalidArgumentError to be raised. As far as I can tell, these are
  not required by any existing internal conversion function.
diff: @@ -1165,8 +1165,7 @@ def internal_convert_to_tensor(value,
  try:
  ret = conversion_func(
  value, dtype=preferred_dtype, name=name, as_ref=as_ref)
  - except (TypeError, ValueError, errors.UnimplementedError,
  - errors.InvalidArgumentError):
  + except (TypeError, ValueError):
  # Could not coerce the conversion to use the preferred dtype.
  ret = None
  