public static Read read() {
    // 1000 for batch size is good enough in many cases,
    // ex: if document size is large, around 10KB, the response's size will be around 10MB
    // if document seize is small, around 1KB, the response's size will be around 1MB
    return new AutoValue_SolrIO_Read.Builder().setBatchSize(1000).setQuery("*:*").build();
  }
@Test
  public void testRead() throws Exception {
    SolrIOTestUtils.insertTestDocuments(SOLR_COLLECTION, NUM_DOCS, solrClient);

    PCollection<SolrDocument> output =
        pipeline.apply(
            SolrIO.read()
                .withConnectionConfiguration(connectionConfiguration)
                .from(SOLR_COLLECTION)
                .withBatchSize(101));
    PAssert.thatSingleton(output.apply("Count", Count.globally())).isEqualTo(NUM_DOCS);
    pipeline.run();
  }