yii\console\controllers\BaseMigrateController::findMigrationPath PHP Method

    private function findMigrationPath($namespace)
    {
        if (empty($namespace)) {
            return $this->migrationPath;
        }
        if (!in_array($namespace, $this->migrationNamespaces, true)) {
            throw new Exception("Namespace '{$namespace}' not found in `migrationNamespaces`");
        }
        return $this->getNamespacePath($namespace);
    }