vl.markGeoshape({"strokeWidth": "2", "stroke": "White",})
.data(bhamGeoFeaturesWithURL)
.transform({ "calculate": "datum.url", "as": "url" })
.encode(
vl.tooltip({"field": "properties.WD21NM"}),
vl.href({"field": "url", "type": "nominal"})
)
.width(500)
.height(500)
.render()