code: func MustParse(s string) Pattern {
  	pattern, err := Parse(s)
  	if err != nil {
  		panic(err)
  	}
  	return pattern
  }
docs: // MustParse parses the pattern according to the specification
  // of Parse. In addition, it panics if there is an error in parsing the
  // given string as a pattern.
  //
  // See Parse for more details.