code: function (x, y, ox, oy, type, fnInit) {
          _jp.Anchors[type] = function (params) {
              var a = params.jsPlumbInstance.makeAnchor([ x, y, ox, oy, 0, 0 ], params.elementId, params.jsPlumbInstance);
              a.type = type;
              if (fnInit) fnInit(a, params);
              return a;
          };
      }
docs: -------- basic anchors ------------------