Question

A bag in java is a kind of collection that doesn’t do much more than contain its items. It does not order the items in any particular order and nor does it prevent duplicates. Develop a java interface named Bag that can store a certain number of whole numbers in it. Provide the following methods in the interface.
• getCurrentSize( ) that returns a count of numbers in the bag
• isEmpty( ) – that checks if the bag is empty
• add (int num) – adds a new number num to the bag
• remove (int num) – removes the first occurrence of the number num from the bag
• remove( ) – removes randomly a number from the bag
• clear( ) – removes all the numbers from the bag
• getFrequencyOf(int num) – counts the number of times the number num exists in the bag
• contains(int num) – Tests whether the bag contains the number num.