code: public static Iterable<Metadata> getAllMetadata(BoxItem item, String ... fields) {
          QueryStringBuilder builder = new QueryStringBuilder();
          if (fields.length > 0) {
              builder.appendParam("fields", fields);
          }
          return new BoxResourceIterable<Metadata>(
                  item.getAPI(),
                  GET_ALL_METADATA_URL_TEMPLATE.buildWithQuery(item.getItemURL().toString(), builder.toString()),
                  DEFAULT_LIMIT) {
  
              @Override
              protected Metadata factory(JsonObject jsonObject) {
                  return new Metadata(jsonObject);
              }
  
          };
      }
docs: Used to retrieve all metadata associated with the item.
  @param item item to get metadata for.
  @param fields the optional fields to retrieve.
  @return An iterable of metadata instances associated with the item.