public static SyntaxNode AddWarningComment(this SyntaxGenerator g, SyntaxNode node)
 {
    return node.AddLeadingTrivia(
       g.Comment("/*****************************************************************/"),
       g.NewLine(),
       g.Comment("/* WARNING! THIS CODE IS AUTOMATICALLY GENERATED. DO NOT MODIFY! */"),
       g.NewLine(),
       g.Comment("/*****************************************************************/")
    );
 }