private string?ReadModel(GeneratorExecutionContext context) { var sb = new StringBuilder(); var files = context.GetKayleeModelFiles(); foreach (var file in files) { var text = file.GetText(context.CancellationToken); if (text == null) { context.ReportDiagnostic(Diagnostic.Create(FailedToReadFileError, Location.None, file.Path)); return(null); } sb.AppendLine(text.ToString()); } return(sb.ToString()); }