How to put a dot on top (or maybe change the colour) of a candle from a method in a helper class that does not extend Indicator?

I'm creating a cBot to try and automate my trading strategy and for that I'm creating a Candle class that will hold the methods that I will use on my trading strategy (i.e. previousCandle.IsBullishEngulfing()). 

I would like mark the candle with a small dot on the top from some methods, such as the IsBullishEngulfing. The code that I see only works with indicators, not with cBots. 

/algos/indicators/show/142

I don't think it's right to have my helper class Candle inheriting methods from the Indicator class, but if that's the only option then I'll do it. 

Just wondering if there's another way to draw on the chart. 

Thanks.