num pivotX

The x-coordinate of the pivot point of this display object.

The pivot point is the point this display Object rotates around. It is also the anchor point for the x/y-coordinates and the center for all transformations like scaling.

The default pivot point is (0,0).

Source 

@override
num get pivotX => _pivotX;
void pivotX=(num value)

Source 

@override
set pivotX(num value) {
  if (value is num) _pivotX = value;
  _transformationMatrixRefresh = true;
}