consumer: (BufferedSource) -> T,
    sizeMapper: (T) -> Int,
  ): T {
    val contentLength = contentLength()
    if (contentLength > Int.MAX_VALUE) {
      throw IOException("Cannot buffer entire body for content length: $contentLength")
    }

    val bytes = source().use(consumer)
    val size = sizeMapper(bytes)
    if (contentLength != -1L && contentLength != size.toLong()) {