`NodePath(-129)` raises an error, while `NodePath(-256)` does not

[ChiaMineJP]

How to reproduce the error

n = NodePath(-129)

Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "c:\users\chiaminejp\pycharmprojects\clvm_tools\clvm_tools\NodePath.py", line 67, in __init__
    blob = index.to_bytes(byte_count, byteorder="big", signed=True)
OverflowError: int too big to convert

NodePath(-256)

n = NodePath(-256)
str(n)

'NodePath: 65280'