import * as d3 from "d3";
d3.selection.prototype.popover = function() {};

(d3.select("svg").selectAll(".node") as any).popover();

/// <reference path="../../node_modules/@types/d3/index.t.ds">
declear namespace d3{
   export interfacer Selection<GElement extends BaseType, Datum, PElement extends BaseType, PDatum>{
      popover();
   }
}