code: def _init_glyph(self, plot, mapping, properties):
          
          tile_source = mapping['tile_source']
          level = properties.pop('level', 'underlay')
          renderer = plot.add_tile(tile_source, level=level)
          renderer.alpha = properties.get('alpha', 1)
  
          # Remove save tool
          plot.tools = [t for t in plot.tools if not isinstance(t, SaveTool)]
          return renderer, tile_source
docs: Returns a Bokeh glyph object.