docs: function(change) {
              var changeX = change.x,
                  changeY = change.y,
                  x = this.getX(),
                  y = this.getY();
  
              if(changeX !== undefined) {
                  x += changeX;
              }
  
              if(changeY !== undefined) {
                  y += changeY;
              }
  
              this.setPosition({x:x, y:y});
              return this;
          }