在二叉搜索树中计算高度的最佳方法是什么？

class TreeNode:
    def __init__(self, value=0, left=None, right=None):
        self.value = value
        self.left = left
        self.right = right

def calculate_height(node):
    if node is None:
        return 0
    left_height = calculate_height(node.left)
    right_height = calculate_height(node.right)
    return max(left_height, right_height) + 1

# 示例
root = TreeNode(1)
root.left = TreeNode(2)
root.right = TreeNode(3)
root.left.left = TreeNode(4)
root.left.right = TreeNode(5)

height = calculate_height(root)
print("Height of the binary search tree:", height)