public static <T> Stringifier<T> checkInstance(Stringifier<T> stringifier) {
		return INSTANCE==stringifier?null:stringifier;
	}
public static < T > Stringifier < T > checkInstance ( Stringifier < T > stringifier ) { return INSTANCE == stringifier ? null : stringifier ; }
Check whether stringifier is the NoneStringifier
@param stringifier Stringifier to compare with NoneStringifier
@return null when stringifier==NoneStringifier, else given stringifier