@classmethod
def from_file(cls, filename, encoder=None, decoder=None, **kwargs):
    """ Return a new JSONSettings from a JSON file.
            Arguments:
                filename  : File name to read.

            All open() and json.load() exceptions are propagated.
        """
    settings = cls(filename=filename, encoder=encoder, decoder=decoder)
    settings.load(**kwargs)
    return settings
