assertThat(response.body.string()).isEqualTo("abc")

    assertFailsWith<IllegalStateException> {
      response.peekBody(3)
    }
  }

  /**
   * Returns a new response body that refuses to be read once it has been closed. This is true of
   * most [BufferedSource] instances, but not of [Buffer].
   */
  private fun responseBody(content: String): ResponseBody {
    val data = Buffer().writeUtf8(content)