void loadExisting(WikidataTranslations oldMappings) throws IOException {
    LongObjectMap<Map<String, String>> alreadyHave = oldMappings.getAll();
    LongObjectMap<Instant> alreadyHaveUpdateTimes = oldMappings.getUpdateTimes();
    if (!alreadyHave.isEmpty()) {
      LOGGER.info("skipping {} mappings we already have", alreadyHave.size());
      writeTranslations(alreadyHave, alreadyHaveUpdateTimes);
      for (LongObjectCursor<Map<String, String>> cursor : alreadyHave) {
        visited.add(cursor.key);
      }
    }
  }
Make an HTTP request to wikidata's <a href="https://www.wikidata.org/wiki/Wikidata:SPARQL_query_service">sparql
endpoint</a> to fetch name translations for a set of QIDs.
planetiler-core/src/main/java/com/onthegomap/planetiler/util/Wikidata.java