Change spacer width/height without sizepolicy

There's no possibility to change spacer size without sizepolicy. Problem is that user may want to change width or height value without touching to current policy. Specific issue could be that QUiLoader loads dynamically UI that spacer size is wanted to change and there's no possibility to get current policy for it. UI form might be implemented by third party. Spacer setGeometry also doesn't work for this. It just updates internal rect value but not update spacer width/height.

So three options suggested:
1. Let setGeometry() change width and height
2. Give access to get current size policy.
3. Provide new changeSize() method that let size policy unchanged