Okhttp - define constants and initialize objects

   //Create a queue for asynchronous calls
    private Request request;

    //Thread blocking method call
    private Response response;

    // access object
    private Call call;

    //okhttp instance
    private OkHttpClient mOkHttpClient;

    // get, post status code requested by thread blocking mode
    private final static int GET_INSTANCE = 0;
    private final static int POST_INSTANCE = 1;

    //default timeout
    private final static int VALUE_DEFAULT_TIME_OUT = 20 * 1000;

    /**
     * Parameter Type
     * "text", text
     * "image", picture
     * "audio", audio
     * "video", video
     * "object", other
     */
    private static final MediaType MEDIA_TYPE_TEXT = MediaType.parse("text/x-markdown; charset=utf-8");
    private static final MediaType MEDIA_TYPE_JPG = MediaType.parse("image/png");
    private static final MediaType MEDIA_TYPE_AUDIO = MediaType.parse("audio/mp3");
    private static final MediaType MEDIA_TYPE_VIDEO = MediaType.parse("video/mp4");
    private static final MediaType MEDIA_TYPE_OBJECT = MediaType.parse("application/octet-stream");
    private static final MediaType MEDIA_TYPE_JSON = MediaType.parse("application/json; charset=utf-8");

// tag for each network request
    public static final String TAG_DATA = "tag_data";
    public static final String TAG_IMAGE = "tag_image";
    public static final String TAG_FILE = "tag_file";

private RequestHandle() {
        //Create okHttpClient object
        mOkHttpClient = new OkHttpClient();
        mOkHttpClient.setConnectTimeout(VALUE_DEFAULT_TIME_OUT, TimeUnit.MILLISECONDS);//Connection timeout
        mOkHttpClient.setReadTimeout(VALUE_DEFAULT_TIME_OUT, TimeUnit.MILLISECONDS);//Read timeout
        mOkHttpClient.setWriteTimeout(VALUE_DEFAULT_TIME_OUT, TimeUnit.MILLISECONDS);//Write timeout
    }