class ActiveRecord::ConnectionAdapters::SavepointTransaction

def commit
  connection.release_savepoint(savepoint_name) if materialized?
  @state.commit!
end

def full_rollback?; false; end

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

def materialize!
  connection.create_savepoint(savepoint_name)
  super
end

def rollback
  connection.rollback_to_savepoint(savepoint_name) if materialized?
  @state.rollback!
end