private fun KtExpression.getPossiblyQualifiedSimpleNameExpression(): KtSimpleNameExpression? {
    return ((this as? KtQualifiedExpression)?.selectorExpression ?: this) as? KtSimpleNameExpression?
}

/**
 * Helper abstraction to navigate through qualified FIR elements - we have to match [ClassId] and PSI qualifier pair
 * to correctly reason about long qualifiers.
 */
private sealed interface TypeQualifier {