@ApiMethod(name = "getAllUnclaimedLeftovers")
public Collection<Leftover> getAllUnclaimedLeftovers() {
    Collection<Leftover> unclaimedLeftoverOffers = new ArrayList<Leftover>();

    for(Leftover leftover : ofy().load().type(Leftover.class)) {
        if (!leftover.isClaimed() && leftover.isValid()) {
            unclaimedLeftoverOffers.add(leftover);
        }
    }

    return unclaimedLeftoverOffers;
}

public static Collection<Leftover> getAllUnclaimedLeftovers() throws IOException {
    try {
        return Proxy.getEndpoint().getAllUnclaimedLeftovers().execute().getItems();
    } catch (IOException e) {
        Log.d("DataStore_UnclaimedLeftovers_Error", e.getMessage());
        throw e;
    }
}

private class UnclaimedLeftoversTask extends AsyncTask<Void, Void, Void> {

    @Override
    protected Void doInBackground(Void... params) {
        try {
            setUnclaimedLeftovers(LeftoverProxy.getAllUnclaimedLeftovers());
            setIsUnclaimedLeftoversSucceeded(true);
            return null;
        } catch (IOException e) {
            setIsUnclaimedLeftoversSucceeded(false);
            return null;
        } catch (NullPointerException e) {
            setIsUnclaimedLeftoversSucceeded(false);
            return null;
        }
    }
}

public GetAllUnclaimedLeftovers getAllUnclaimedLeftovers() throws java.io.IOException {
    GetAllUnclaimedLeftovers result = new GetAllUnclaimedLeftovers();
    initialize(result);
    return result;
}

public class GetAllUnclaimedLeftovers extends EndpointRequest<com.frigoshare.endpoint.model.LeftoverCollection> {

    private static final String REST_PATH = "leftovercollection";


    protected GetAllUnclaimedLeftovers() {
      super(Endpoint.this, "GET", REST_PATH, null,   com.frigoshare.endpoint.model.LeftoverCollection.class);
    }

...
}

public EndpointRequest(
  Endpoint client, String method, String uriTemplate, Object content, Class<T> responseClass) {
    super(
        client,
        method,
        uriTemplate,
        content,
        responseClass);
    }

/**
   * Sends the metadata request to the server and returns the parsed metadata response.
   *
   * <p>
   * Subclasses may override by calling the super implementation.
   * </p>
   *
   * @return parsed HTTP response
   */
  public T execute() throws IOException {
    HttpResponse response = executeUnparsed();
    if (Void.class.equals(responseClass)) {
      response.ignore();
      return null;
    }
    return response.parseAs(responseClass);
  }