public MessageBuilder resetStyle() {
        return this;
    }

    @Override
    public MessageBuilder append(CharSequence cs) {
        buffer.append(cs);
        return this;
    }

    @Override
    public MessageBuilder append(CharSequence cs, int start, int end) {
        buffer.append(cs, start, end);
        return this;
    }

    @Override
    public MessageBuilder append(char c) {
        buffer.append(c);

    public MessageBuilder resetStyle() {
        return this;
    }

    @Override
    public MessageBuilder append(CharSequence cs) {
        buffer.append(cs);
        return this;
    }

    @Override
    public MessageBuilder append(CharSequence cs, int start, int end) {
        buffer.append(cs, start, end);
        return this;
    }

    @Override
    public MessageBuilder append(char c) {
        buffer.append(c);

                buildNumber = null;
            }
        }
    }

    private static boolean isDigits(String cs) {
        if (cs == null || cs.isEmpty()) {
            return false;
        }
        final int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (!Character.isDigit(cs.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    //
    // message building methods modelled after Ansi methods
    //

    @Nonnull
    @Override
    MessageBuilder append(CharSequence cs);

    @Nonnull
    @Override
    MessageBuilder append(CharSequence cs, int start, int end);

    @Nonnull
    @Override
    MessageBuilder append(char c);

    /**
     * Append content to the message buffer.
     *