public boolean swapChildren(@NonNull DisplayObject child1,@NonNull DisplayObject child2){
  child1.swapPriority(child2);
  int childIndex1=mDisplayList.indexOf(child1);
  int childIndex2=mDisplayList.indexOf(child2);
  if (childIndex1 == -1 || childIndex2 == -1) {
    return false;
  }
  removeChildAt(childIndex1);
  addChildAt(childIndex1,child2);
  removeChildAt(childIndex2);
  addChildAt(childIndex2,child1);
  return true;
}

public boolean swapChildren ( @ NonNull DisplayObject child1 , @ NonNull DisplayObject child2 ) { child1 . swapPriority ( child2 ) ; int childIndex1 = mDisplayList . indexOf ( child1 ) ; int childIndex2 = mDisplayList . indexOf ( child2 ) ; if ( childIndex1 == - 1 || childIndex2 == - 1 ) { return false ; } removeChildAt ( childIndex1 ) ; addChildAt ( childIndex1 , child2 ) ; removeChildAt ( childIndex2 ) ; addChildAt ( childIndex2 , child1 ) ; return true ; }
swaps the specified children ' s depth in the display list . if either child is not a child of this container , return false .
