}
  }
}

private fun Char.charCode() =
  code.toString(16).let {
    if (it.length < 2) {
      "0$it"
    } else {
      it
    }
  }

internal fun commonHeadersOf(vararg inputNamesAndValues: String): Headers {
  require(inputNamesAndValues.size % 2 == 0) { "Expected alternating header names and values" }

  // Make a defensive copy and clean it up.