Return a function taking an integer point size argument that returns
        |True| if the text in this fitter can be wrapped to fit entirely
        within its extents when rendered at that point size.

def _fits_inside_predicate(self):
        """
        Return a function taking an integer point size argument that returns
        |True| if the text in this fitter can be wrapped to fit entirely
        within its extents when rendered at that point size.
        """
        def predicate(point_size):
            """
            Return |True| if the text in *line_source* can be wrapped to fit
            entirely within *extents* when rendered at *point_size* using the
            font defined in *font_file*.
            """
            text_lines = self._wrap_lines(self._line_source, point_size)
            cy = _rendered_size('Ty', point_size, self._font_file)[1]
            return (cy * len(text_lines)) <= self._height

        return predicate