val p2 = response.peekBody(2)
    assertThat(response.body.string()).isEqualTo("abcdef")
    assertThat(p1.string()).isEqualTo("abcd")
    assertThat(p2.string()).isEqualTo("ab")
  }

  @Test fun negativeStatusCodeThrowsIllegalStateException() {
    assertFailsWith<IllegalStateException> {
      newResponse(responseBody("set status code -1"), -1)
    }
  }

  @Test fun zeroStatusCodeIsValid() {