NerdsAndCompany\Schematic\Behaviors\Schematic::isInstalled PHP Method

    public function isInstalled()
    {
        if (!isset($this->_isInstalled)) {
            try {
                // First check to see if DbConnection has even been initialized, yet.
                if (Craft::app()->getComponent('db')) {
                    // If the db config isn't valid, then we'll assume it's not installed.
                    if (!Craft::app()->getIsDbConnectionValid()) {
                        return false;
                    }
                } else {
                    return false;
                }
            } catch (\Exception $e) {
                return false;
            }
            $this->_isInstalled = Craft::app()->db->tableExists('info', false);
        }
        return $this->_isInstalled;
    }