static String getErrorMessage(Reply reply) {
        if (!reply.hasErrors()) {
            return null;
        }
        StringBuilder errors = new StringBuilder();
        for (int i = 0; i < reply.getNumErrors(); ++i) {
            errors.append(reply.getError(i)).append(" ");
        }
        return errors.toString();
    }
Returns a concatenated error string from the errors contained in a reply.

@param reply The reply whose errors to concatenate.
@return The error string.
documentapi/src/main/java/com/yahoo/documentapi/messagebus/MessageBusAsyncSession.java