<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def validate(self):
 """ Check if an access token is valid Returns: dict: Empty or error dict """

        endpoint = '/validate'

        payload = dict(accessToken=self.access_token)
        rep = self._ygg_req(endpoint, payload)
        return not bool(rep)