def clean(self):
        """
        Make sure that the scope is less or equal to the previous scope!
        """
        data = self.cleaned_data

        if "scope" in data and not scope.check(data.get("scope"), data.get("refresh_token").access_token.scope):
            raise OAuthValidationError({"error": "invalid_scope"})

        return data
    def clean(self):
        """
        Make sure that the scope is less or equal to the scope allowed on the
        grant! 
        """
        data = self.cleaned_data
        # Only check if we've actually got a scope in the data
        # (read: All fields have been cleaned)
        if "scope" in data and not scope.check(data.get("scope"), data.get("grant").scope):
            raise OAuthValidationError({"error": "invalid_scope"})

        return data