///|
fn main raise @adapters.AdapterError {
  let db = @core.new_db().init()
  let chunk = db.make_chunk()
  let items = @adapters.parse_danuni_json(
    "[{\"DMID\":\"example\",\"content\":\"hello MoonBit\"}]",
  )
  chunk.upsert(items)
  println(@adapters.export_danuni_json(chunk.danmakus()))
}