As you already know from the lecture, function hierarchies are used to structure the functionality of the system interface considered in the RE$-$task. $1.$ Create a function hierarchy by extending or refining the individual system functionalities from the use case Reserve an E$-$Scooter with the app. Relate the elaborated collection of functions to each other using decomposition and dependency. $2.$ Specify input and output channels for your leaf$-$functions. $3.$ Identify additional relationships between the functions, e$.$g$.,$excludes$/$XOR$,$interrupts$,$as alternative to$,$precedes$,$enables$/$disables$,$follows$,$data $($flow$)$ dependency$.4.$ Provide an important reason for creating and using a function hierarchy. How is a function hierarchy different from the functions in the use case?