/**
   * {@inheritdoc}
   */
  public function getDatasource($datasource_id) {
    $datasources = $this->getDatasources();

    if (empty($datasources[$datasource_id])) {
      $index_label = $this->label();
      throw new SearchApiException("The datasource with ID '$datasource_id' could not be retrieved for index '$index_label'.");
    }

    return $datasources[$datasource_id];
  }

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    "status":0,
    "QTime":1,
    "params":{
      "q":"",
      "indent":"on"}},
  "response":{"numFound":0,"start":0,"docs":[]
  }}