code: function(diffX, diffY) {
          var el = this.getEl();
  
          if (!this.DDM.verifyEl(el)) {
              if (el && el.style && (el.style.display == 'none')) {
                  this.logger.log(this.id + " can not get initial position, element style is display: none");
              } else {
                  this.logger.log(this.id + " element is broken");
              }
              return;
          }
  
          var dx = diffX || 0;
          var dy = diffY || 0;
  
          var p = Dom.getXY( el );
  
          this.initPageX = p[0] - dx;
          this.initPageY = p[1] - dy;
  
          this.lastPageX = p[0];
          this.lastPageY = p[1];
  
          this.logger.log(this.id + " initial position: " + this.initPageX + 
                  ", " + this.initPageY);
  
  
          this.setStartPosition(p);
      }
docs: Stores the initial placement of the linked element.
  @method setInitialPosition
  @param {int} diffX   the X offset, default 0
  @param {int} diffY   the Y offset, default 0
  @private