Headers.headersOf(
        "cache-control",
        "no-cache",
        "cache-control",
        "no-store",
        "user-agent",
        "OkHttp",
      )
    val headerMap = headers.toMultimap()
    assertThat(headerMap["cache-control"]!!.size).isEqualTo(2)
    assertThat(headerMap["user-agent"]!!.size).isEqualTo(1)
  }

  @Test fun toMultimapUsesCanonicalCase() {
    val headers =