allRowsProcessed example

if (empty($this->requirements)) {
      // There are no requirements to check.       return;
    }
    /** @var \Drupal\migrate\Plugin\MigrationInterface[] $required_migrations */
    $required_migrations = $this->getMigrationPluginManager()->createInstances($this->requirements);

    $missing_migrations = array_diff($this->requirements, array_keys($required_migrations));
    // Check if the dependencies are in good shape.     foreach ($required_migrations as $migration_id => $required_migration) {
      if (!$required_migration->allRowsProcessed()) {
        $missing_migrations[] = $migration_id;
      }
    }
    if ($missing_migrations) {
      throw new RequirementsException('Missing migrations ' . implode(', ', $missing_migrations) . '.', ['requirements' => $missing_migrations]);
    }
  }

  /** * Gets the migration plugin manager. * * @return \Drupal\migrate\Plugin\MigrationPluginManagerInterface * The migration plugin manager. */