src/Listify.php
protected function getListifyConfigValue($key)
    {
        return array_key_exists($key, $this->listifyConfig) ? $this->listifyConfig[ $key ] : null;
    }
protected function getListifyConfigValue($key)
    {
        return array_key_exists($key, $this->listifyConfig) ? $this->listifyConfig[ $key ] : null;
    }
protected function getListifyConfigValue ( $ key ) { return array_key_exists ( $ key , $ this -> listifyConfig ) ? $ this -> listifyConfig [ $ key ] : null ; }
Returns a config value by key, or null if it does not exist.

@param string $key
@return null|mixed
Returns a config value by key or null if it does not exist .