class Sequel::Database

def add_transaction(conn, opts)

Add the current thread to the list of active transactions 
def add_transaction(conn, opts)
  if supports_savepoints?
    unless @transactions[conn]
      @transactions[conn] = {:savepoint_level=>0}
      @transactions[conn][:prepare] = opts[:prepare] if supports_prepared_transactions?
    end
  else
    @transactions[conn] = {}
    @transactions[conn][:prepare] = opts[:prepare] if supports_prepared_transactions?
  end
end