final public function delete($code) {

        if ( array_key_exists($code, $this->rpc_errors) ) {

            unset($this->rpc_errors[$code]);

            $this->logger->debug("Deleted error $code");

            return true;

        } else {

            $this->logger->warning("Cannot delete error $code: entry not found");

            return false;

        }

    }