Pihrtsoft.Text.RegularExpressions.Linq.PatternBuilder.AppendGroupReferenceInternal C# (CSharp) Method

        internal void AppendGroupReferenceInternal(int groupNumber)
        {
            AppendInternal('\\');
            AppendDirect(groupNumber);

            if (!_fFormat && Settings.HasOptions(PatternOptions.SeparateGroupNumberReference))
                AppendDirect("(?:)");

            if (_fBuilder)
                _builder.AddInfo(SyntaxKind.GroupReference);
        }

 internal override void AppendTo(PatternBuilder builder)
 {
     builder.AppendGroupReferenceInternal(GroupNumber);
 }