private void appendGroupInstanceDecoderDisplay(
        final StringBuilder sb,
        final List<Token> fields,
        final List<Token> groups,
        final List<Token> varData,
        final String baseIndent)
    {
        final String indent = baseIndent + INDENT;

        sb.append('\n');
        append(sb, indent, "public StringBuilder appendTo(final StringBuilder builder)");
        append(sb, indent, "{");
        append(sb, indent, "    if (null == buffer)");
        append(sb, indent, "    {");
        append(sb, indent, "        return builder;");
        append(sb, indent, "    }");
        sb.append('\n');
        Separator.BEGIN_COMPOSITE.appendToGeneratedBuilder(sb, indent + INDENT);
        appendDecoderDisplay(sb, fields, groups, varData, indent + INDENT);
        Separator.END_COMPOSITE.appendToGeneratedBuilder(sb, indent + INDENT);
        sb.append('\n');
        append(sb, indent, "    return builder;");
        append(sb, indent, "}");
    }
\n" +
                "     * Field presence indication. Can be optional, required, or constant.\n" +
                "
sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/java/JavaGenerator.java