👉 A "undoer" in programming refers to an object or function that performs a specific task and returns the original value of the same variable when it is called. The purpose of this object or function is to restore the state of the program after a certain action, such as changing a variable's value or performing a specific operation. For example, if we have a function `doSomething` that takes an integer argument and prints its value, and we call `undoer.doSomething(10)`
