internal object FirSyntheticFunctionInterfaceSourceProvider {
    fun findPsi(fir: FirDeclaration): PsiElement? {
        return when (fir) {
            is FirSimpleFunction -> provideSourceForInvokeFunction(fir)
            is FirClass -> provideSourceForFunctionClass(fir)
            else -> null
        }
    }

    private fun provideSourceForInvokeFunction(function: FirSimpleFunction): PsiElement? {