code: def count(self, minval, maxval, include_min=True, include_max=True):
          '''Returns the number of elements in the skiplist with a score
          between min and max.
          '''
          rank1 = self.rank(minval)
          if rank1 < 0:
              rank1 = -rank1 - 1
          elif not include_min:
              rank1 += 1
          rank2 = self.rank(maxval)
          if rank2 < 0:
              rank2 = -rank2 - 1
          elif include_max:
              rank2 += 1
          return max(rank2 - rank1, 0f count(self, minval, maxval, include_min=True, include_max=True):
          '''Returns the number of elements in the skiplist with a score
          between min and max.
          '''
          rank1 = self.rank(minval)
          if rank1 < 0:
              rank1 = -rank1 - 1
          elif not include_min:
              rank1 += 1
          rank2 = self.rank(maxval)
          if rank2 < 0:
              rank2 = -rank2 - 1
          elif include_max:
              rank2 += 1
          return max(rank2 - rank1, 0)
docs: Returns the number of elements in the skiplist with a score
          between min and max.