builder.header("key", "sample\tvalue")
    assertFailsWith<IllegalArgumentException> {
      builder.header("sample\tkey", "value")
    }
  }

  @Test
  fun headerForbidsControlCharacters() {
    assertForbiddenHeader("\u0000")
    assertForbiddenHeader("\r")
    assertForbiddenHeader("\n")
    assertForbiddenHeader("\u001f")
    assertForbiddenHeader("\u007f")