Method isInstalled

/**
 * Checks if a component is installed
 *
 * @param   string  $option  The component option.
 *
 * @return  integer
 *
 * @since   3.4
 */
public static function isInstalled($option)
{
    $components = static::getComponents();
    return isset($components[$option]) ? 1 : 0;
}