Method checkIfCoreExtension

/**
 * Check if an extension is core or not
 *
 * @param   string   $type      The extension's type.
 * @param   string   $element   The extension's element name.
 * @param   integer  $clientId  The extension's client ID. Default 0.
 * @param   string   $folder    The extension's folder. Default ''.
 *
 * @return  boolean  True if core, false if not.
 *
 * @since   3.7.4
 */
public static function checkIfCoreExtension($type, $element, $clientId = 0, $folder = '')
{
    return \in_array(array($type, $element, $folder, $clientId), self::$coreExtensions);
}