code: function leftTooSmall(node) {
  		if (balanceFactor(node) >= -1) { return node; }   // Left is not too small, don't change
  		if (balanceFactor(node.right) > 0) {rightRotation(node.right);}
  		return leftRotation(node);
  	}
docs: Modify the tree if its left subtree is too small compared to the right
  Return the new root if any