Real-Time Event Averager

You are tasked with designing and implementing a class that processes a continuous stream of events in real time. Each event is associated with a timestamp (an integer representing seconds since the epoch). The class should support the following operations:

1. add_event(timestamp): Add an event with the given timestamp.

2. get_average(current_time): Calculate and return the average number of events per minute for events that occurred in the last 60 seconds (i.e., for events with timestamps in the range (current_time - 60, current_time]).

Guidelines:

• Your solution should correctly handle a high volume of events in real time.
• Choose appropriate data structures to efficiently add events and retrieve the count of events in the required time window.
• You may assume that the events are added in non-decreasing order of their timestamps, but your solution should not rely solely on this unless explicitly managed.
• Consider edge cases, such as when there are no events in the last 60 seconds.

Implement your solution in the programming language of your choice. Your submission should include code that demonstrates the functionality of the class, showing how events are added and how the average is reported when queried.