documentUpdateIndex = "fess.update";

        // Create mock SearchEngineClient
        searchEngineClient = new SearchEngineClient() {
            @Override
            public long deleteByQuery(String index, QueryBuilder query) {
                deleteByQueryCalled = true;
                deleteIndex = index;
                deleteQuery = query;
                return 1L;
            }
        };

     *
     * @param index The index name
     * @param queryString The query string
     * @return The SuggestDeleteResponse
     */
    public SuggestDeleteResponse deleteByQuery(final String index, final String queryString) {
        return deleteByQuery(index, QueryBuilders.queryStringQuery(queryString).defaultOperator(Operator.AND));
    }

    /**
     * Deletes suggest items by a query builder.
     *

                return oldDocList;
            }

            @Override
            public long deleteByQuery(final String index, final QueryBuilder queryBuilder) {
                if (queryBuilder instanceof final TermsQueryBuilder termsQueryBuilder) {

        throw new UnsupportedOperationException("not yet.");
    }

    @Override
    public SuggestWriterResult deleteByQuery(final Client client, final SuggestSettings settings, final String index,
            final QueryBuilder queryBuilder) {
        throw new UnsupportedOperationException("deleteByQuery is unsupported.");
    }

     */
    public SuggestDeleteResponse deleteByQuery(final String queryString) {
        ensureOperations();
        return deletionOps.deleteByQuery(index, queryString);
    }

    /**
     * Deletes suggest items by a query builder.
     * @param queryBuilder The query builder.
     * @return The SuggestDeleteResponse.
     */
    public SuggestDeleteResponse deleteByQuery(final QueryBuilder queryBuilder) {

     * @throws OpenSearchAccessException if the deletion fails.
     * @deprecated Use {@link #deleteByQuery(String, QueryBuilder)} instead. The type parameter is no longer used.
     */
    @Deprecated
    public int deleteByQuery(final String index, final String type, final QueryBuilder queryBuilder) {
        return deleteByQuery(index, queryBuilder);
    }

    /**

        }
        return result;
    }

    @Override
    public SuggestWriterResult deleteByQuery(final Client client, final SuggestSettings settings, final String index,
            final QueryBuilder queryBuilder) {
        final SuggestWriterResult result = new SuggestWriterResult();
        try {
            SuggestUtil.deleteByQuery(client, settings, index, queryBuilder);
        } catch (final Exception e) {

        }).when(mockClearScrollBuilder).execute(any(ActionListener.class));

        final int deleted = fesenClient.deleteByQuery("test-index", QueryBuilders.matchAllQuery());

        assertEquals(1, deleted);
        verify(mockClearScrollBuilder, times(1)).addScrollId("scroll1");
    }

    /**
     * Test: deleteByQuery deprecated method delegates to new method
     * Verifies backward compatibility
     */
    @Test

     * @param queryBuilder the query that defines which documents to delete
     * @return a result object containing information about the delete operation
     */
    SuggestWriterResult deleteByQuery(Client client, SuggestSettings settings, String index, QueryBuilder queryBuilder);

    /**
     * Merges an array of SuggestItem objects by combining items with the same ID.
     *

            /* No-op */ }
    }

    private static class FastMockSearchEngineClient extends SearchEngineClient {
        @Override
        public long deleteByQuery(String index, QueryBuilder queryBuilder) {
            return 0L;
        }
    }

    private static class FastMockDataConfigBhv extends DataConfigBhv {
        // Minimal implementation
    }