':param trader_id: The trader id who created the message
:param message_number: The number of the message created
:type trader_id: TraderId
:type message_number: MessageNumber'

def __init__(self, trader_id, message_number):

    super(MessageId, self).__init__()
    assert isinstance(trader_id, TraderId), type(trader_id)
    assert isinstance(message_number, MessageNumber), type(message_number)
    self._trader_id = trader_id
    self._message_number = message_number
