code: def feature_extraction(self, algorithms):
          
          assert type(algorithms) is list
          features = []
          for algorithm in algorithms:
              new_features = algorithm(self)
              assert len(new_features) == algorithm.get_dimension(), \
                  "Expected %i features from algorithm %s, got %i features" % \
                  (algorithm.get_dimension(), str(algorithm), len(new_features))
              features += new_features
          return features
docs: Get a list of features.
  
          Every algorithm has to return the features as a list.