skipInvalid example

$destination_ids = NULL;
    $source_id_values = [];
    foreach ($lookup_migration_ids as $lookup_migration_id) {
      $lookup_value = $value;
      if ($lookup_migration_id == $this->migration->id()) {
        $self = TRUE;
      }
      if (isset($this->configuration['source_ids'][$lookup_migration_id])) {
        $lookup_value = array_values($row->getMultiple($this->configuration['source_ids'][$lookup_migration_id]));
      }
      $lookup_value = (array) $lookup_value;
      $this->skipInvalid($lookup_value);
      $source_id_values[$lookup_migration_id] = $lookup_value;

      // Re-throw any PluginException as a MigrateException so the executable       // can shut down the migration.       try {
        $destination_id_array = $this->migrateLookup->lookup($lookup_migration_id, $lookup_value);
      }
      catch (PluginNotFoundException $e) {
        $destination_id_array = [];
      }
      catch (MigrateException $e) {