title: SpriteKit: cannot change node position in contact callback
body: <p>I have a node with a dynamic physics body. And I would like to make it static and change its position when it comes in contact with another body.</p>
  
  <p>I managed to make the body static with the solution provided in this question: <a href="https://stackoverflow.com/questions/20462295">Sprite Kit failing assertion: (typeA == b2_dynamicBody || typeB == b2_dynamicBody)</a></p>
  
  <p>However if I change the <code>position</code> property of the node in one of the contact callback methods (e.g <code>didBeginContact</code>) the new position is not taken into account.</p>
  
  <p>How could I achieve that?</p>