code: def from_file(cls, fpath, position=1, file_id=None):
          
          if file_id is None:
              file_id = fpath
          with open(fpath) as f:
              code = f.read()
              file_content = str(code)
              file_metadata = FileMetadata(file_id, position)
              return cls(file_metadata, file_content)
docs: Convience method to create a kappa file object from a file on disk
  
          Inputs
          ------
          fpath -- path to the file on disk
          position -- (default 1) rank among all files of the model while parsing
              see FileMetadata
          file_id -- (default = fpath) the file_id that will be used by kappa.