### Question:
BufferedSolrInputDocumentWriter implements SolrInputDocumentWriter { @Override public void deleteByQuery(String deleteQuery) throws SolrServerException, IOException { delegateWriter.deleteByQuery(deleteQuery); } BufferedSolrInputDocumentWriter(SolrInputDocumentWriter delegateWriter, int bufferSize,
            Counter documentOutputCounter, Counter documentBatchOutputCounter); @Override void add(int shard, Map<String, SolrInputDocument> inputDocumentMap); @Override void deleteById(int shard, List<String> idsToDelete); @Override void deleteByQuery(String deleteQuery); void flush(); @Override void close();  }### Answer:
@Test public void testDeleteByQuery() throws SolrServerException, IOException { bufferedWriter.deleteByQuery("name:x"); verify(delegateWriter).deleteByQuery("name:x"); }