class ActiveRecord::ConnectionAdapters::Transaction

def initialize(connection, isolation: nil, joinable: true, run_commit_callbacks: false)
  super()
  @connection = connection
  @state = TransactionState.new
  @callbacks = nil
  @records = nil
  @isolation_level = isolation
  @materialized = false
  @joinable = joinable
  @run_commit_callbacks = run_commit_callbacks
  @lazy_enrollment_records = nil
  @dirty = false
  @user_transaction = joinable ? ActiveRecord::Transaction.new(self) : ActiveRecord::Transaction::NULL_TRANSACTION
  @instrumenter = TransactionInstrumenter.new(connection: connection, transaction: @user_transaction)
end