JakeWharton Update to OkHttp 3.11
Use get instead of parse for HttpUrl and MediaType where valid input is always required.
Latest commit ce71d05 Jul 13, 2018

README.md

Retrofit Converters

Retrofit ships with support for OkHttp's RequestBody and ResponseBody types but the library is content-format agnostic. The child modules contained herein are additional converters for other popular formats.

To use, supply an instance of your desired converter when building your Retrofit instance.

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("https://api.example.com")
    .addConverterFactory(GsonConverterFactory.create())
    .build();