protected function getKey($key, $default = null)
    {
        return ($this->isIntegerable($key, true)) ? $this->getIntegerable($key, $default)
                                                  : $this->getStringable($key, $default);
    }
protected function getKey($key, $default = null)
    {
        return ($this->isIntegerable($key, true)) ? $this->getIntegerable($key, $default)
                                                  : $this->getStringable($key, $default);
    }
protected function getKey ( $ key , $ default = null ) { return ( $ this -> isIntegerable ( $ key , true ) ) ? $ this -> getIntegerable ( $ key , $ default ) : $ this -> getStringable ( $ key , $ default ) ; }
Retrieve proper key.

@param mixed $key
@param null|mixed $default
@return int|string
Retrieve proper key .