import this and we want to ease upgrades for their users.


## Version 4.0.0-RC2

_2019-06-21_

 *  New: Require Kotlin 1.3.40.
 *  New: Change the Kotlin API from `File.toRequestBody()` to `File.asRequestBody()` and
    `BufferedSource.toResponseBody()` to `BufferedSource.asResponseBody()`. If the returned value
    is a view of what created it, we use _as_.
 *  Fix: Permit response codes of zero for compatibility with OkHttp 3.x.

    requestBody = byteArrayOf(0, 1).toRequestBody(null, 0, 2)
    requestBody = byteArrayOf(0, 1).toRequestBody("".toMediaTypeOrNull(), 0, 2)
    requestBody = File("").asRequestBody(null)
    requestBody = File("").asRequestBody("".toMediaTypeOrNull())
  }

  @Test
  fun response() {
    val response: Response = Response.Builder().build()
    val request: Request = response.request