val signature = StringCharacterIterator(canonicalSignature)
        val javaType = SignatureParsing.parseTypeString(signature, StubBuildingVisitor.GUESSING_MAPPER)
        val typeInfo = TypeInfo.fromString(javaType, false)
        val typeText = TypeInfo.createTypeText(typeInfo) ?: return null

        return SyntheticTypeElement(useSitePosition, typeText)
    }

    val signature = StringCharacterIterator(canonicalSignature)
    val javaType = SignatureParsing.parseTypeString(signature, StubBuildingVisitor.GUESSING_MAPPER)
    val typeInfo = TypeInfo.fromString(javaType, false)
    val typeText = TypeInfo.createTypeText(typeInfo) ?: return null

    return SyntheticTypeElement(useSitePosition, typeText)
}

        if (function.bodyBlockExpression != null) {
            // Given `fun f(...): R { blockExpression }`, `{ blockExpression }` is mapped to the enclosing anonymous function,
            // which may raise an exception if we attempt to retrieve, e.g., callable declaration from it.
            return null
        }

    add(FirErrors.REDUNDANT_NULLABLE) { firDiagnostic ->
        RedundantNullableImpl(
            firDiagnostic as KtPsiDiagnostic,
            token,
        )
    }
    add(FirErrors.PLATFORM_CLASS_MAPPED_TO_KOTLIN) { firDiagnostic ->
        PlatformClassMappedToKotlinImpl(
            firDiagnostic.a,
            firDiagnostic as KtPsiDiagnostic,
            token,
        )
    }