HttpClient.java

public class HttpClient {
    private static final String API_BASE_URL = "https://jsonplaceholder.typicode.com/";

    private static Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(API_BASE_URL)
            .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
            .addConverterFactory(GsonConverterFactory.create())
            .build();

    private static ApiService apiService = retrofit.create(ApiService.class);

    public static ApiService getApiService() {
        return apiService;
    }
}