code: public List<Database> listDatabases(String instanceId) {
      // [START listDatabases]
      Page<Database> page = dbAdminClient.listDatabases(instanceId, Options.pageSize(1));
      List<Database> dbs = new ArrayList<>();
      while (page != null) {
        Database db = Iterables.getOnlyElement(page.getValues());
        dbs.add(db);
        page = page.getNextPage();
      }
      // [END listDatabases]
      return dbs;
    }
docs: [VARIABLE my_instance_id]