name: String,
    tagClass: Int,
    tag: Long,
    block: (BufferedSink) -> Unit,
  ) {
    val constructedBit: Int
    val content = Buffer()

    stack.add(content)
    constructed = false // The enclosed object written in block() is not constructed.
    path += name
    try {
      block(content)
      constructedBit = if (constructed) 0b0010_0000 else 0
      constructed = true // The enclosing object is constructed.