public function get(string $key = null)
    {
        $result = (null !== $key)
            ? $this->_config[$key] ?? null
            : $this->_config;

        return $result;
    }
public function get(string $key = null)
    {
        $result = (null !== $key)
            ? $this->_config[$key] ?? null
            : $this->_config;

        return $result;
    }
public function get ( string $ key = null ) { $ result = ( null !== $ key ) ? $ this -> _config [ $ key ] ?? null : $ this -> _config ; return $ result ; }
Get single parameter by name or null, or all available parameters

@param   string|null $key
@return  mixed
Get single parameter by name or null or all available parameters