code: func conflictingFlags(resp http.ResponseWriter, req *http.Request, flags ...string) bool {
  	params := req.URL.Query()
  
  	found := false
  	for _, conflict := range flags {
  		if _, ok := params[conflict]; ok {
  			if found {
  				resp.WriteHeader(http.StatusBadRequest)
  				fmt.Fprint(resp, "Conflicting flags: "+params.Encode())
  				return true
  			}
  			found = true
  		}
  	}
  
  	return false
  }
docs: // conflictingFlags determines if non-composable flags were passed in a request.