code: func (p *Parser) Parse(tokenString string, keyFunc Keyfunc) (*Token, error) {
  	return p.ParseWithClaims(tokenString, MapClaims{}, keyFunc)
  }
docs: // Parse, validate, and return a token.
  // keyFunc will receive the parsed token and should return the key for validating.
  // If everything is kosher, err will be nil