private fun PsiElement.isWhileLoopCondition() =
        unwrapQualified<KtWhileExpressionBase> { whileExpr, cond -> whileExpr.condition == cond } != null

    private fun PsiElement.isIfCondition() =
        unwrapQualified<KtIfExpression> { ifExpr, cond -> ifExpr.condition == cond } != null

    override fun isDefinitelyNull(expression: KtExpression): Boolean =

            // but also as implicit parameter types, for example in setters with implicit types
            is ConeFlexibleType -> {
                // since Kotlin decompiler always "renders" flexible types as their lower bound, we can do the same here
                lowerBound.renderTypeAsKotlinType()
            }

            else -> errorWithFirSpecificEntries("Type should not be present in Kotlin declaration", coneType = this)