修改之前外连接代码，使用类。

class ExternalService:
    def __init__(self, url):
        self.url = url

    def connect(self):
        # connect to external service using self.url
        return True

    def disconnect(self):
        # disconnect from external service
        return True

class MyClass:
    def __init__(self, external_service):
        self.external_service = external_service

    def do_something(self):
        if self.external_service.connect():
            # do something using the external service
            self.external_service.disconnect()
        else:
            # handle connection error
            pass

# create an instance of ExternalService
external_service = ExternalService('https://example.com')

# create an instance of MyClass and pass the ExternalService instance as a parameter
my_class = MyClass(external_service)

# call do_something method to use the external service
my_class.do_something()