Recursion is a process where a function calls itself one or more times with modified values to accomplish a task. This technique can be particularly effective when solving complex problems that can be broken down into smaller, simpler problems of the same type. In the provided code, the count$\_$users function uses recursion to count the number of users that belong to a group within a company's system. It does this by iterating through each member of a group, and if a member is another group, it recursively calls count$\_$users to count the users within that subgroup. However, there is a bug in the code! Can you spot the problem and fix it$?$