我不能遍历嵌套的字典

def traverse_dict(dictionary):
    for key, value in dictionary.items():
        if isinstance(value, dict):
            traverse_dict(value)
        else:
            print(f"Key: {key}, Value: {value}")

# 示例字典
nested_dict = {
    'key1': 'value1',
    'key2': {
        'key3': 'value3',
        'key4': {
            'key5': 'value5',
            'key6': 'value6'
        }
    }
}

traverse_dict(nested_dict)

Key: key1, Value: value1
Key: key3, Value: value3
Key: key5, Value: value5
Key: key6, Value: value6