new_contents: from django.test import SimpleTestCase
  from mock import ANY, patch
  
  from corehq.apps.es.tests.utils import es_test
  from corehq.elastic import SerializationError, get_es_new
  from corehq.util.es.interface import ElasticsearchInterface
  
  
  @es_test
  class TestESInterface(SimpleTestCase):
  
      @classmethod
      def setUpClass(cls):
          super().setUpClass()
          cls.es = get_es_new()
  
      def _validate_es_scan_search_params(self, scan_query, search_query):
          """Call ElasticsearchInterface.scan() and test that the resulting API
          search parameters match what we expect.
  
          Notably:
          - Search call does not include the `search_type='scan'`.
          - Calling `scan(..., query=scan_query, ...)` results in an API call
            where `body == search_query`.
          """
          interface = ElasticsearchInterface(self.es)
          skw = {
              "index": "et",
              "doc_type": "al",
              "request_timeout": ANY,
              "scroll": ANY,
              "size": ANY,
          }
          with patch.object(self.es, "search") as search:
              try:
                  list(interface.scan(skw["index"], scan_query, skw["doc_type"]))
              except SerializationError:
                  # fails to serialize the Mock object.
                  pass
              search.assert_called_once_with(body=search_query, **skw)
  
      def test_scan_no_searchtype_scan(self):
          """Tests that search_type='scan' is not added to the search parameters"""
          self._validate_es_scan_search_params({}, {"sort": "_doc"})
  
      def test_scan_query_extended(self):
          """Tests that sort=_doc is added to an non-empty query"""
          self._validate_es_scan_search_params({"_id": "abc"},
                                               {"_id": "abc", "sort": "_doc"})
  
      def test_scan_query_sort_safe(self):
          """Tests that a provided a `sort` query will not be overwritten"""
          self._validate_es_scan_search_params({"sort": "_id"}, {"sort": "_id"})
  
subject: Add tests for previous commit