code: def apply_range(self, sampfrom=0, sampto=None):
          
          sampto = sampto or self.sample[-1]
  
          kept_inds = np.intersect1d(np.where(self.sample>=sampfrom),
                                     np.where(self.sample<=sampto))
  
  
          for field in ['sample', 'label_store', 'subtype', 'chan', 'num']:
              setattr(self, field, getattr(self, field)[kept_inds])
  
          self.aux_note = [self.aux_note[i] for i in kept_inds]
  
          self.ann_len = len(self.sample)
docs: Filter the annotation attributes to keep only items between the
          desired sample values