public synchronized boolean insertDocument(String tableName, Map<String, Object> document) {
    return insertDocuments(tableName, ImmutableList.of(document));
  }
@Test
  public void testInsertDocumentsShouldThrowErrorWhenCassandraThrowsException() {

    doThrow(RejectedExecutionException.class)
        .when(cassandraClient)
        .execute(any(SimpleStatement.class));

    assertThrows(
        CassandraResourceManagerException.class,
        () -> testManager.insertDocument(COLLECTION_NAME, new HashMap<>()));
  }