code: func NewMustRegexpMatcher(name, pattern string) Matcher {
  	re, err := regexp.Compile(pattern)
  	if err != nil {
  		panic(err)
  	}
  	return &regexpMatcher{name: name, re: re}
  
  }
docs: // NewMustRegexpMatcher returns a new matcher verifying that a value matches
  // the regular expression pattern. Will panic if the pattern is not a valid
  // regular expression.