code: def upgrade_v16_to_v17(storage: SQLiteStorage, old_version: int, current_version: int, **kwargs):
      
      if old_version == SOURCE_VERSION:
          _transform_snapshots(storage)
  
      return TARGET_VERSION
docs: InitiatorPaymentState was changed so that the "initiator"
      attribute is renamed to "initiator_transfers" and converted to a list.