code: function closedPolygon(coordinates) {
      var outer = [ ];
  
      for (var i = 0; i < coordinates.length; i++) {
        var inner = coordinates[i].slice();
        if (pointsEqual(inner[0], inner[inner.length - 1]) === false) {
          inner.push(inner[0]);
        }
  
        outer.push(inner);
      }
  
      return outer;
    }
docs: /*
  Internal: Returns a copy of coordinates for s closed polygon