Method discover

/**
 * Extension discover method
 *
 * Asks each adapter to find extensions
 *
 * @return  InstallerExtension[]
 *
 * @since   3.1
 */
public function discover()
{
    $results = array();
    foreach ($this->getAdapters() as $adapter) {
        $instance = $this->loadAdapter($adapter);
        // Joomla! 1.5 installation adapter legacy support
        if (method_exists($instance, 'discover')) {
            $tmp = $instance->discover();
            // If its an array and has entries
            if (\is_array($tmp) && \count($tmp)) {
                // Merge it into the system
                $results = array_merge($results, $tmp);
            }
        }
    }
    return $results;
}