### Question:
DirectSolrInputDocumentWriter implements SolrInputDocumentWriter { @Override public void deleteByQuery(String deleteQuery) throws SolrServerException, IOException { try { solrServer.deleteByQuery(deleteQuery); } catch (SolrException e) { if (isDocumentIssue(e)) { documentDeleteErrorMeter.mark(1); } else { solrDeleteErrorMeter.mark(1); throw e; } } catch (SolrServerException sse) { solrDeleteErrorMeter.mark(1); throw sse; } } DirectSolrInputDocumentWriter(String indexName, SolrClient solrServer); @Override void add(int shard, Map<String, SolrInputDocument> inputDocumentMap); @Override void deleteById(int shard, List<String> idsToDelete); @Override void deleteByQuery(String deleteQuery); @Override void close();  }### Answer:
@Test public void testDeleteByQuery() throws SolrServerException, IOException { String deleteQuery = "_delete_query_"; solrWriter.deleteByQuery(deleteQuery); verify(solrServer).deleteByQuery(deleteQuery); }