runImport example

// Make sure that a user with uid 2 exists.     $this->container
      ->get('entity_type.manager')
      ->getStorage('user')
      ->create([
        'uid' => 2,
        'name' => $this->randomMachineName(),
        'status' => 1,
      ])
      ->save();

    $this->runImport([
      'source' => [
        'plugin' => 'embedded_data',
        'data_rows' => [
          [
            'id' => '1',
            'name' => $this->randomString(256),
            'user_id' => '1',
          ],
          [
            'id' => '2',
            'name' => $this->randomString(64),