This rule applies whenever an if statement is followed by one or more else if statements; the final else if
should be followed by an else statement.
The requirement for a final else statement is defensive programming.
The else statement should either take appropriate action or contain a suitable comment as to why no action is taken. This is
consistent with the requirement to have a final case _ clause in a match.
if (x == 0) {
doSomething
} else if (x == 1) {
doSomethingElse
}
if (x == 0) {
doSomething
} else if (x == 1) {
doSomethingElse
} else {
throw new IllegalStateException
}