in uber-core/src/main/java/com/uber/sdk/core/auth/AuthorizationCodeGrantFlow.java [88:95]
private static OAuth2Service createOAuthService(String baseUrl) {
final Moshi moshi = new Moshi.Builder().add(new OAuthScopesAdapter()).build();
return new Retrofit.Builder()
.baseUrl(baseUrl)
.addConverterFactory(MoshiConverterFactory.create(moshi))
.build()
.create(OAuth2Service.class);
}