判断「以下Python代码创建的树是完全二叉树」这一表述是否正确

以下代码创建的树是一棵完全二叉树：

class TreeNode:
    def __init__(self, val=0, left=None, right=None):
        self.val = val
        self.left = left
        self.right = right
root = TreeNode(1)
root.left = TreeNode(2)
root.right = TreeNode(3)
root.left.left = TreeNode(4)