Many functions require a call to super at some point in the overriden
function. This is however not checked by the compiler and is left for
the developer to check the documentation whether a call to super is
required. Not calling super when expected leads to bugs that are many
times hard to track.
I propose adding a keyword (ex. overriderequiressupercall or
requiressupercall) to mark a function that requires its subclass
override to call super at some point, thus making it a compile failure
when the super call is omitted.