docs: def open_get_line(filename, limit=-1, **kwargs):
      """Opens the password file named @filename and reads first @limit
      passwords. @kwargs are passed to get_line for further processing.
      For example, pw_filter etc.
      @fielname: string
      @limit: integer
      """
      allowed_keys_for_get_line = {'sep', 'pw_filter', 'errors'}
      for k in list(kwargs.keys()):
          if k not in allowed_keys_for_get_line:
              del kwargs[k]
      print("After filtering: {}".format(kwargs))
      with open_(filename, 'rt') as f:
          for w, c in get_line(f, limit, **kwargs):
              yield w, c