void IDictionary.Add(object key, object value)
{
switch (key)
{
case null:
// key could be null
// ConcurrentDictionary hates null
throw new ArgumentNullException(nameof(key));
case TKey keyAsTKey when value is TValue valueAsTValue:
_wrapped.AddNew(keyAsTKey, valueAsTValue);
break;
default:
break;
}
throw new ArgumentException(string.Empty, nameof(value));
}