code: func (s *SkipList) GetGreaterOrEqual(min interface{}) (actualKey, value interface{}, ok bool) {
  	candidate := s.getPath(s.header, nil, min)
  
  	if candidate != nil {
  		return candidate.key, candidate.value, true
  	}
  	return nil, nil, false
  }
docs: // GetGreaterOrEqual finds the node whose key is greater than or equal
  // to min. It returns its value, its actual key, and whether such a
  // node is present in the skip list.