code: func ReqHostMatches(regexps ...*regexp.Regexp) ReqConditionFunc {
  	return func(req *http.Request, ctx *ProxyCtx) bool {
  		for _, re := range regexps {
  			if re.MatchString(req.Host) {
  				return true
  			}
  		}
  		return false
  	}
  }
docs: // ReqHostMatches returns a ReqCondition, testing whether the host to which the request was directed to matches
  // any of the given regular expressions.