@class NSString; @interface PGFeatureExtractor : MAFeatureExtractor <PGFeatureExtractorProtocol> @property (readonly, nonatomic) long long featureLength; @property (readonly) unsigned long long hash; @property (readonly) Class superclass; @property (readonly, copy) NSString *description; @property (readonly, copy) NSString *debugDescription; + (id)featureExtractor; @end