if (axis == X_AXIS) return offsetsX[childIndex]; else return offsetsY[childIndex];
if (axis != X_AXIS && axis != Y_AXIS) throw new IllegalArgumentException("Illegal axis argument"); return offsets[axis][childIndex];
  protected int getOffset(int axis, int childIndex)  {    if (axis == X_AXIS)      return offsetsX[childIndex];    else      return offsetsY[childIndex];  }