@Test fun ofTrims() {
    val headers = headersOf("\t User-Agent \n", " \r OkHttp ")
    assertThat(headers.name(0)).isEqualTo("User-Agent")
    assertThat(headers.value(0)).isEqualTo("OkHttp")
  }

  @Test fun ofThrowsOddNumberOfHeaders() {
    assertFailsWith<IllegalArgumentException> {
      headersOf("User-Agent", "OkHttp", "Content-Length")
    }
  }

  @Test fun ofThrowsOnEmptyName() {
    assertFailsWith<IllegalArgumentException> {