<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def wrap_handler(self, api_types, methods, endpoints):
 """ Allow for a handler to be wrapped in a chain. :param api_types: Types to wrap handlers for :param methods: Methods to wrap handlers for :param endpoints: Endpoints to wrap handlers for """


        def wrapper(fn):
            @wraps(fn)
            def wrapped(*args, **kwargs):
                return fn(*args, **kwargs)

            for api_type in api_types:
                for method in methods:
                    for endpoint in endpoints:
                        key = (api_type, method, endpoint)
                        self._handler_chains.setdefault(key, [])
                        self._handler_chains[key].append(wrapped)
            return wrapped

        return wrapper