classdef Subject
    methods(Abstract)
        request(~);
    end
end

classdef RealSubject < Subject    
    methods
        function request(obj)
            mc = metaclass(obj);
            disp(mc.Name + ":request");
        end
    end 
end

classdef Proxy < Subject
    properties
        sub
    end
    methods
        function obj = Proxy(sub)
            obj.sub = sub;
        end
        function request(obj)
            if(randi([0,1]))
                obj.before();
                obj.sub.request();
                obj.after();
            else
                mc = metaclass(obj);
                disp(mc.Name + ":no request");
            end
        end
        function before(obj)
            mc = metaclass(obj);
            disp(mc.Name + ":start request");
        end
        function after(obj)
            mc = metaclass(obj);
            disp(mc.Name + ":end request");
        end
    end
end

a = RealSubject();
a.request();
 
b = Proxy(a);
b.request();