docs: def authenticate(self):
          """Authenticate user by any means and return either true or false.
  
          Args:
  
          Returns:
              tuple (is_valid, username): True is valid user, False if not
          """
          basic_auth = request.authorization
          is_valid = False
          user = None
          if basic_auth:
              is_valid, user = self.check_basic_auth(
                  basic_auth.username, basic_auth.password
              )
          else:  # Try token auth
              token = request.headers.get('Authorization', None)
              param_token = request.args.get('access_token')
              if token or param_token:
                  if token:
                      # slice the 'token ' piece of the header (following
                      # github style):
                      token = token[6:]
                  else:
                      # Grab it from query dict instead
                      token = param_token
                  log.debug('Received token: %s', token)
  
                  is_valid, user = self.check_token_auth(token)
          return (is_valid, user)