/**
         * Not all expressions appear in the [ControlFlowGraph].
         * Still, if we find at least some of them, it's very unlikely that we will ever find a better graph.
         */
        val firCandidates = buildSet {
            fun addCandidate(firCandidate: FirElement) {
                add(firCandidate)

        CannotCheckForErasedImpl(
            firSymbolBuilder.typeBuilder.buildKtType(firDiagnostic.a),
            firDiagnostic as KtPsiDiagnostic,
            token,
        )
    }
    add(FirErrors.CAST_NEVER_SUCCEEDS) { firDiagnostic ->
        CastNeverSucceedsImpl(
            firDiagnostic as KtPsiDiagnostic,
            token,
        )
    }
    add(FirErrors.USELESS_CAST) { firDiagnostic ->

        function: FirSimpleFunction,
        other: FirLiteralExpression<*>
    ): FirLiteralExpression<*>? {
        if (value == null || other.value == null) return null
        // NB: some utils accept very general types, and due to the way operation map works, we should up-cast rhs type.
        val rightType = when {
            function.symbol.callableId.isStringEquals -> CompileTimeType.ANY