new

# File activerecord/lib/active_record/connection_adapters/abstract/transaction.rb, line 324
      def initialize(connection, savepoint_name, parent_transaction, **options)
        super(connection, **options)

        parent_transaction.state.add_child(@state)

        if isolation_level
          raise ActiveRecord::TransactionIsolationError, "cannot set transaction isolation in a nested transaction"
        end

        @savepoint_name = savepoint_name
      end