Converter.kt

fun <R> TypeAdapter<R>.convertResponse(onConvert: TypeAdapter<R>.(ResponseBody) -> R): Converter<ResponseBody, R> =
    Converter<ResponseBody, R> { onConvert(it) }

fun <T> TypeAdapter<T>.convertRequest(onConvert: TypeAdapter<T>.(T) -> RequestBody): Converter<T, RequestBody> =
    Converter<T, RequestBody> { onConvert(it) }

fun <T, R, I : Converter<in T, out R>> I.wrap(onConvert: I.(T) -> R): Converter<T, R> =
    Converter<T, R> { this@wrap.onConvert(it) }