text: # Definition for a binary tree node.
  # class TreeNode:
  #     def __init__(self, val=0, left=None, right=None):
  #         self.val = val
  #         self.left = left
  #         self.right = right
  class Solution:
      def invertTree(self, root: TreeNode) -> TreeNode:
          if root is None:
              return
          left = self.invertTree(root.left)
          right = self.invertTree(root.right)
          root.left = right
          root.right = left
          return root
      # * Runtime ~ 24ms
      # * Top 92%