Using a method in another class
 

Good day, colleagues.
I turn to the point, there is a class (A) with a method of zeroing the delivery price. There is a second class (B), in which the logic of obtaining discounts on products occurs. The question itself, at a certain point in the logic of class (B), I need to call the method of class (A).
I did not find another solution, how can I set a free shipping price.
P.S. when I create a class object and call it I call the method I need, I get an error (Too few arguments to function XLite \ Logic \ Order \ Modifier \ AModifier :: __ construct (),) I don’t understand how I can override the constructor.
__________________