As far as I know you can’t have multiple definitions of the same function/method except when overriding the definition in another library in which case only the last definition is used (but you can call the super definition within the method)
By using default parameter values or the ‘@’ when specifying your parameter list for a function/method you can allow quite a lot of flexibility in the way the function/method is called (especially if you’re naming the arguments), but you’d still need to handle the different combinations of arguments in the one method.