code: func (m *MinWise) Cardinality() int {
  
  	// http://www.cohenwang.com/edith/Papers/tcest.pdf
  
  	sum := 0.0
  
  	for _, v := range m.minimums {
  		sum += -math.Log(float64(math.MaxUint64-v) / float64(math.MaxUint64))
  	}
  
  	return int(float64(len(m.minimums)-1) / sum)
  }
docs: // Cardinality estimates the cardinality of the set