private TreeNode setPos(TreeNode newNode, int pos, int endPos) {
    return newNode.setPosition(new SourcePosition(pos, endPos - pos, lineNumber(pos)));
  }
private TreeNode setPos ( TreeNode newNode , int pos , int endPos ) { return newNode . setPosition ( new SourcePosition ( pos , endPos - pos , lineNumber ( pos ) ) ) ; }
Set a TreeNode's position using begin and end source offsets. Its line number
is unchanged.