if (getPreferredSpan(getAxis()) != height) preferenceChanged(this, false, true);
  protected void layout(int width, int height)  {    int flowAxis = getFlowAxis();    if (flowAxis == X_AXIS)      {        if (layoutSpan != width)          {            layoutChanged(Y_AXIS);        layoutSpan = width;      }      }    else      {        if (layoutSpan != height)          {            layoutChanged(X_AXIS);        layoutSpan = height;      }      }    if (layoutDirty)      {      strategy.layout(this);        layoutDirty = false;      }    if (getPreferredSpan(getAxis()) != height)      preferenceChanged(this, false, true);    super.layout(width, height);  }