public T setEnableSource(boolean enableSource) {
    attributes.put("_source", ImmutableSortedMap.of(ENABLED, enableSource));
    return castThis();
  }
@Test
  @UseDataProvider("indexWithAndWithoutRelations")
  public void index_without_source(Index index) {
    NewIndex newIndex = new SimplestNewIndex(IndexType.main(index, "foo"), defaultSettingsConfiguration);
    newIndex.setEnableSource(false);

    assertThat(getAttributeAsMap(newIndex, "_source")).containsExactly(entry("enabled", false));
  }