fun foo(): Int {     // +1 VIOLATION
    return 1 
}
 
fun foo() = 1        // +0 good
 
fun foo(): Int {     // +0  because instruction is a "if" statement
   if (toto) {
       return 1
    }
}
 
fun foo(): Int {     // +0  because instruction is a "if" statement
   if (toto) {
       return 1
    }
}
 
// +0 because the instruction is written over at least 5 lines.
public inline fun <T, K> Iterable<T>.groupingBy(crossinline keySelector: (T) -> K): Grouping<T, K> {
    return object : Grouping<T, K> {
        override fun sourceIterator(): Iterator<T> = this@groupingBy.iterator()
        override fun keyOf1(element: T): K = keySelector(element1)
        override fun keyOf2(element: T): K = keySelector(element2)
    }
}