in src/Microsoft.Azure.Relay/WebSockets/NetEventSource.Common.cs [467:484]
private static string Format(FormattableString s)
{
switch (s.ArgumentCount)
{
case 0: return s.Format;
case 1: return string.Format(s.Format, Format(s.GetArgument(0)));
case 2: return string.Format(s.Format, Format(s.GetArgument(0)), Format(s.GetArgument(1)));
case 3: return string.Format(s.Format, Format(s.GetArgument(0)), Format(s.GetArgument(1)), Format(s.GetArgument(2)));
default:
object[] args = s.GetArguments();
object[] formattedArgs = new object[args.Length];
for (int i = 0; i < args.Length; i++)
{
formattedArgs[i] = Format(args[i]);
}
return string.Format(s.Format, formattedArgs);
}
}