Custom response class CoinbaseResponse.

CoinbaseResponse.kt

/**
 * A response class that holds a success and error body type as well
 * as a throwable for network errors.
 *
 * @param T success response body type.
 * @param U error response body type.
 * @param body set when a call succeeds with a 2xx status code.
 * @param errorBody set when a call fails with a non-2xx calls status code.
 * @param networkError set when a network error occurs.
 */
data class CoinbaseResponse<T : Any, U : Any>(
    val body: T?,
    val errorBody: U?,
    val networkError: IOException?)

/**
 * Sample service that returns a stream of [CoinbaseResponse].
 */
interface OAuthApi {
    @POST("token")
    fun authToken(@Body body: TokenRequestBody)
            : Single<CoinbaseResponse<AccessToken, OAuthError>>
}