val value = namesAndValues[i + 1]
    headersCheckName(name)
    headersCheckValue(value, name)
  }

  return Headers(namesAndValues)
}

internal fun Map<String, String>.commonToHeaders(): Headers {
  // Make a defensive copy and clean it up.
  val namesAndValues = arrayOfNulls<String>(size * 2)
  var i = 0
  for ((k, v) in this) {
    val name = k.trim()
    val value = v.trim()