display text. font_desc is string of pango font description
           often handier than calling this function directly, is to create
           a class:Label object

def show_layout(self, text, font_desc, alignment = pango.Alignment.LEFT,
                    width = -1, wrap = None, ellipsize = None,
                    single_paragraph_mode = False):
        """display text. font_desc is string of pango font description
           often handier than calling this function directly, is to create
           a class:Label object
        """
        layout = self._cache_layout = self._cache_layout or pangocairo.create_layout(cairo.Context(cairo.ImageSurface(cairo.FORMAT_A1, 0, 0)))
        self._add_instruction("show_layout", layout, text, font_desc,
                              alignment, width, wrap, ellipsize, single_paragraph_mode)