code: def from_file(cls, fn, *args, **kwargs):
          
          return AmiraHeader(get_parsed_data(fn, *args, **kwargs))
docs: Constructor to build an AmiraHeader object from a file
          
          :param str fn: Amira file
          :return ah: object of class ``AmiraHeader`` containing header metadata
          :rtype: ah: :py:class:`ahds.header.AmiraHeader`