This code defines a new class called `SizedStack` that extends...

This code defines a new class called SizedStack that extends the built-in Java class Stack and has a generic type parameter T. The SizedStack class also has an instance variable maxSize that determines the maximum size of the stack.

The push method is overridden in the SizedStack class to limit the number of elements that can be added to the stack. When an element is pushed onto the stack, the push method first checks if the current size of the stack is less than the maxSize. If it is, then the push method calls the push method from its super class, Stack, to add the object to the stack. However, if the size of the stack is already at the maxSize, then an exception is thrown with the message "At capacity".