spyOn(markdownDatasets, 'getAggregations').and.returnValue(
        Immutable.fromJS([
          { key: 'id1', label: 'label1', filtered: { doc_count: 25 } },
          { key: 'id2', label: 'label2', filtered: { doc_count: 33 } },
          { key: 'id3', label: 'label3', filtered: { doc_count: 13 } },