code: def openid_authorization_validator(self, request):
          
          request_info = super(ImplicitGrant, self).openid_authorization_validator(request)
          if not request_info:  # returns immediately if OAuth2.0
              return request_info
  
          # REQUIRED. String value used to associate a Client session with an ID
          # Token, and to mitigate replay attacks. The value is passed through
          # unmodified from the Authentication Request to the ID Token.
          # Sufficient entropy MUST be present in the nonce values used to
          # prevent attackers from guessing values. For implementation notes, see
          # Section 15.5.2.
          if not request.nonce:
              raise InvalidRequestError(
                  request=request,
                  description='Request is missing mandatory nonce parameter.'
              )
          return request_info
docs: Additional validation when following the implicit flow.