private static void ValidateProvider(LoggingProviderBase provider, LoggingProviderChain chain)
{
ThrowWhenProviderIsInChain(provider, chain);
// Note that LoggingProviderChain is immutable. Adding involves creating a new instance.
var chainWithProvider = chain.Add(provider);
CheckAllReferencedProviders(provider.GetReferencedProviders(), chainWithProvider);
}
