code: func removeDuplicate(s []string) []string {
  	m := map[string]bool{}
  	for _, v := range s {
  		if v != "" && !m[v] {
  			s[len(m)] = v
  			m[v] = true
  		}
  	}
  	s = s[:len(m)]
  	return s
  }
docs: // Remove duplicates or string