Method setInstance

/**
 * Returns a reference to the a Log object, only creating it if it doesn't already exist.
 * Note: This is principally made available for testing and internal purposes.
 *
 * @param   Log  $instance  The logging object instance to be used by the static methods.
 *
 * @return  void
 *
 * @since   1.7.0
 */
public static function setInstance($instance)
{
    if ($instance instanceof Log || $instance === null) {
        static::$instance =& $instance;
    }
}