'Initialises the TickEvent.
Parameters:
ticker - The ticker symbol, e.g. \'GOOG\'.
time - The timestamp of the tick
bid - The best bid price at the time of the tick.
ask - The best ask price at the time of the tick.'

def __init__(self, ticker, time, bid, ask):

    self.type = EventType.TICK
    self.ticker = ticker
    self.time = time
    self.bid = bid
    self.ask = ask
