val response = newResponse(responseBody("abcdef"))
    val peekedBody = response.peekBody(3)
    assertThat(peekedBody.string()).isEqualTo("abc")
    assertThat(response.body.string()).isEqualTo("abcdef")
  }

  @Test fun peekLongerThanResponse() {
    val response = newResponse(responseBody("abc"))
    val peekedBody = response.peekBody(6)
    assertThat(peekedBody.string()).isEqualTo("abc")

  }

  @Test fun peekAfterReadingResponse() {
    val response = newResponse(responseBody("abc"))
    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].
   */