@classmethod
def from_json(cls, fname: Union[(str, Path)], open_kwargs: dict={}):
    with fsspec.open(str(fname), mode='rt', **open_kwargs) as fh:
        jblob = json.loads(fh.read())
    return cls(**jblob)
@classmethod
def from_json(cls, fname: Union[(str, Path)], open_kwargs: dict={}):
    with fsspec.open(str(fname), mode='rt', **open_kwargs) as fh:
        jblob = json.loads(fh.read())
    return cls(**jblob)