-- input --
2022-01-01 opening balances
    assets                    21 = 21
    equity:opening/closing balances
-- expect --
Journal
  Transaction j:1:1-4:1
    Date: 2022-01-01
    Payee: "opening balances" j:1:12-2:0
    Posting j:2:1-3:1
      Account j:2:5-2:11
        SubAccount: "assets" j:2:5-2:11
      Amount j:2:31-2:31
        Quantity: 21
        Commodity: ""
        CommodityPos: Before
        HasSpace: false
        Precision: 0
        Decimal: "."
      BalanceAssertion j:2:34-3:0
        IsStrict: false
        IsInclusive: false
        Amount j:2:36-2:36
          Quantity: 21
          Commodity: ""
          CommodityPos: Before
          HasSpace: false
          Precision: 0
          Decimal: "."
    Posting j:3:1-4:1
      Account j:3:5-4:0
        SubAccount: "equity" j:3:5-3:11
        SubAccount: "opening/closing balances" j:3:12-4:0
      Amount: <elided>