code: def store(self, moments):
          
          if len(self.storage) == self.nsave:  # merge if we must
              # print 'must merge'
              self.storage[-1].combine(moments, mean_free=self.remove_mean)
          else:  # append otherwise
              # print 'append'
              self.storage.append(moments)
          # merge if possible
          while self._can_merge_tail():
              # print 'merge: ',self.storage
              M = self.storage.pop()
              # print 'pop last: ',self.storage
              self.storage[-1].combine(M, mean_free=self.remove_mean)
docs: Store object X with weight w