Apis.java

public class Apis {
    public static StarWarsApi getSwarWarsApi() {
        Gson gson = new GsonBuilder()
                .setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)
                .create();
        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl("http://swapi.co/api/")
                .addConverterFactory(GsonConverterFactory.create(gson))
                .build();
        return retrofit.create(StarWarsApi.class);
    }
}