code: func GetInt(data []byte, keys ...string) (val int64, err error) {
  	v, t, _, e := Get(data, keys...)
  
  	if e != nil {
  		return 0, e
  	}
  
  	if t != Number {
  		return 0, fmt.Errorf("Value is not a number: %s", string(v))
  	}
  
  	return ParseInt(v)
  }
docs: // GetInt returns the value retrieved by `Get`, cast to a int64 if possible.
  // If key data type do not match, it will return an error.