assertFailsWith<IllegalArgumentException> {
      builder.header("Name", s)
    }
    assertFailsWith<IllegalArgumentException> {
      builder.addHeader("Name", s)
    }
  }

  @Test
  fun noTag() {
    val request =
      Request
        .Builder()
        .url("https://square.com")
        .build()
    assertThat(request.tag()).isNull()
    assertThat(request.tag(Any::class.java)).isNull()