Android 如何在java中为yelp使用category_过滤器

请告诉我如何在java中使用yelp API调用的搜索结果中使用category_过滤器。我已经使用Oauth来生成请求参数。在这段代码中，如何为category_filter添加参数

private static final String API_HOST = "api.yelp.com";
static  String DEFAULT_LOCATION = "London"; 
private static final int SEARCH_LIMIT = 20;
private static final String SEARCH_PATH = "/v2/search";
private static final String BUSINESS_PATH = "/v2/business";



request =new OAuthRequest(Verb.GET, "https://" + API_HOST + SEARCH_PATH);
        request.addOAuthParameter(OAuthConstants.TIMESTAMP, seconds.toString());
        request.addHeader(OAuthConstants.TIMESTAMP, seconds.toString());
        request.addQuerystringParameter("term", DEFAULT_TERM);
        request.addQuerystringParameter("location", DEFAULT_LOCATION);
        request.addQuerystringParameter("limit", String.valueOf(SEARCH_LIMIT));