public static EventFieldDeclarationSyntax AddStaticModifier(EventFieldDeclarationSyntax eventFieldDeclaration) { if (eventFieldDeclaration == null) { throw new ArgumentNullException(nameof(eventFieldDeclaration)); } SyntaxTokenList modifiers = eventFieldDeclaration.Modifiers; if (!modifiers.Contains(SyntaxKind.StaticKeyword)) { return(eventFieldDeclaration.InsertModifier(SyntaxKind.StaticKeyword, ModifierComparer.Instance)); } else { return(eventFieldDeclaration); } }