Complete an object-oriented programming exercise designed to simulate the type of work expected in the role.
Implement the classes and methods described in the function signature. Your solution should model the required state, enforce the rules below, and return the requested outputs for each method call.
def simulate_system(operations):
operations is a list of method calls to apply in order. Return a list of results for calls that produce output, in the same order they occur.
def simulate_system(operations):