fun headers(name: String): List<String> = headers.values(name)

  /** Returns the tag attached with [T] as a key, or null if no tag is attached with that key. */
  @JvmName("reifiedTag")
  inline fun <reified T : Any> tag(): T? = tag(T::class)

  /** Returns the tag attached with [type] as a key, or null if no tag is attached with that key. */