code: def fit_from_image(self, data, voxelsize, seeds, unique_cls):
          
          fvs, clsselected = self.features_from_image(data, voxelsize, seeds, unique_cls)
          self.fit(fvs, clsselected)
docs: This Method allows computes feature vector and train model.
  
          :cls: list of index number of requested classes in seeds