def getCoverageLayer(self):
         service_info = TileServiceInfo("Mapillary coverage",u"Mapillary coverage", "http://d2cd86j8eqns9s.cloudfront.net/tiles/{z}/{x}/{y}.png")
         service_info.yOriginTop = 1
         #service_info.epsg_crs_id = 3857
         service_info.zmin = 0
         service_info.zmax = 21
         layer = TileLayer(self, service_info, True)
         self.coverageLayerId = layer.id()
         layer.setAttribution(unicode("Mapillary coverage \u00A9MAPILLARY"))
         #layer.setAttributionUrl("")
         #QgsMapLayerRegistry.instance().addMapLayer(layer, False)
         #toc_root = QgsProject.instance().layerTreeRoot()
         #toc_root.insertLayer(0, layer)
         return layer