val headers =
      Headers.Builder()
        .add("content-length", "99")
        .add("authorization", "peanutbutter")
        .add("proxy-authorization", "chocolate")
        .add("cookie", "drink=coffee")
        .add("set-cookie", "accessory=sugar")
        .add("user-agent", "OkHttp")
        .build()
    assertThat(headers.toString()).isEqualTo(
      """
      |content-length: 99