new

# File activerecord/lib/active_record/connection_adapters/abstract/transaction.rb, line 109
      def initialize(connection, savepoint_name, options)
        super(connection, options)
        if options[:isolation]
          raise ActiveRecord::TransactionIsolationError, "cannot set transaction isolation in a nested transaction"
        end
        connection.create_savepoint(@savepoint_name = savepoint_name)
      end