docs: def return_features_numpy(self, names='all'):
          """
          Returns a 2d numpy array of extracted features
  
          Parameters
          ----------
          names : list of strings, a list of feature names which are to be retrieved from the database, if equal to 'all',
          all features will be returned, default value: 'all'
  
          Returns
          -------
          A numpy array of features, each row corresponds to a single datapoint. If a single feature is a 1d numpy array,
          then it will be unrolled into the resulting array. Higher-dimensional numpy arrays are not supported.
          """
          if self._prepopulated is False:
              raise errors.EmptyDatabase(self.dbpath)
          else:
              return return_features_numpy_base(self.dbpath, self._set_object, self.points_amt, names)