internal static IEnumerable <ISymbol> GetSymbolsOfKnownType(this SeparatedSyntaxList <ArgumentSyntax> syntaxList, KnownType knownType, SemanticModel semanticModel) => syntaxList.GetArgumentsOfKnownType(knownType, semanticModel) .Select(argument => semanticModel.GetSymbolInfo(argument.GetExpression()).Symbol);