code: func (m *BottomK) Merge(m2 *BottomK) {
  	for _, v := range *m2.minimums {
  
  		if len(*m.minimums) < m.size {
  			heap.Push(m.minimums, v)
  			continue
  		}
  
  		if v < (*m.minimums)[0] {
  			(*m.minimums)[0] = v
  			heap.Fix(m.minimums, 0)
  		}
  	}
  }
docs: // Merge combines the signatures of the second set, creating the signature of their union.