<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def cleanup_request(request):
 """ Removes `oauth_` keys from various dicts on the request object, and returns the sanitized version. """

        for method_type in ('GET', 'PUT', 'POST', 'DELETE'):
            block = getattr(request, method_type, { })

            if True in [ k.startswith("oauth_") for k in block.keys() ]:
                sanitized = block.copy()

                for k in sanitized.keys():
                    if k.startswith("oauth_"):
                        sanitized.pop(k)

                setattr(request, method_type, sanitized)

        return request