private static void AddInvocation( HelpBuilder builder, IReadOnlyCollection <ISymbol> symbols, Func <ISymbol, HelpItem> formatter) { if (symbols?.Any() != true) { return; } var helpItems = symbols .Select(formatter).ToList(); var maxWidth = helpItems .Select(line => line.Invocation.Length) .OrderByDescending(textLength => textLength) .First(); foreach (var helpItem in helpItems) { builder.AppendHelpItem(helpItem, maxWidth); } }