log.debug("Witness registration successful: {}", registrationId);
            } else {
                response.setError(message.getErrorMessage());
                log.warn("Witness registration failed: {}", message.getErrorMessage());
            }

            return response;

        } catch (Exception e) {
            throw new IOException("Witness register RPC failed", e);
        }

        return returnCode == ERROR_SUCCESS;
    }

    /**
     * Gets the error message for the current return code.
     *
     * @return a human-readable error message
     */
    public String getErrorMessage() {
        switch (returnCode) {
        case ERROR_SUCCESS:
            return "Success";
        case ERROR_INVALID_PARAMETER:
            return "Invalid parameter";
        case ERROR_INSUFFICIENT_BUFFER: