assertFailsWith<IllegalArgumentException> {
      Request.Builder().addHeader("a\tb", "c")
    }.also { expected ->
      assertThat(expected.message).isEqualTo("Unexpected char 0x09 at 1 in header name: a\tb")
    }
  }

  @Test
  fun responseHeaderNameWithSpacePermitted() {
    server.enqueue(
      MockResponse.Builder()
        .clearHeaders()