SizeRequirements.calculateTiledPositions(targetSpan, null, childReqs,
SizeRequirements.calculateTiledPositions(targetSpan, requirements[axis], childReqs[axis],
  protected void layoutMajorAxis(int targetSpan, int axis, int[] offsets,                                 int[] spans)  {    SizeRequirements[] childReqs = getChildRequirements(axis);    // Calculate the spans and offsets using the SizeRequirements uility    // methods.    SizeRequirements.calculateTiledPositions(targetSpan, null, childReqs,                                             offsets, spans);    layoutValid[axis] = true;  }