code: def _fits_in_width_predicate(self, point_size):
          
          def predicate(line):
              """
              Return |True| if *line* fits in this fitter when rendered at
              *point_size*.
              """
              cx = _rendered_size(line.text, point_size, self._font_file)[0]
              return cx <= self._width
  
          return predicate
docs: Return a function taking a text string value and returns |True| if
          that text fits in this fitter when rendered at *point_size*. Used as
          predicate for _break_line()