These exercises are originally from Grow.rb event to learn how we use method_missing to implement some familiar features.
There are some test files written in Minitest. They don't pass soon after you clone it. You will write implementations so that tests are green.
method_missing: It's a hook that are invoked by Ruby runtime when an object cannot understand a message (a.k.a method). This allows dynamic behavior depending on the method name and arguments.
https://docs.ruby-lang.org/en/3.4/BasicObject.html#method-i-method_missing