else -> null
}

fun FirElement.findPsi(): PsiElement? =
    getAllowedPsi()

fun FirBasedSymbol<*>.findPsi(): PsiElement? {
    return if (this is FirCallableSymbol<*>) {
        fir.unwrapFakeOverridesOrDelegated().findPsi()
    } else {
        fir.findPsi()
    } ?: FirSyntheticFunctionInterfaceSourceProvider.findPsi(fir)
}

/**

import org.jetbrains.kotlin.name.StandardClassIds
import org.jetbrains.kotlin.psi.KtClassOrObject

//todo introduce LibraryModificationTracker based cache?
internal object FirSyntheticFunctionInterfaceSourceProvider {
    fun findPsi(fir: FirDeclaration): PsiElement? {
        return when (fir) {
            is FirSimpleFunction -> provideSourceForInvokeFunction(fir)
            is FirClass -> provideSourceForFunctionClass(fir)
            else -> null

import org.jetbrains.kotlin.analysis.api.components.KtPsiTypeProvider
import org.jetbrains.kotlin.analysis.api.fir.KtFirAnalysisSession
import org.jetbrains.kotlin.analysis.api.fir.findPsi
import org.jetbrains.kotlin.analysis.api.fir.types.KtFirType
import org.jetbrains.kotlin.analysis.api.fir.types.PublicTypeApproximator
import org.jetbrains.kotlin.analysis.api.lifetime.KtLifetimeToken

            }
            return fullSymbolsResolved.mapNotNullTo(mutableSetOf()) { findParentSymbol(it, goBackSteps, selectedFqName) }
        }
    }

    /**
     * Finds the parent symbol of the given [ResolveResult] by traversing back up the symbol hierarchy a [goBackSteps] steps,
     * or until the containing class or object symbol is found.
     *

        val samResolver = FirSamResolver(firSession, analysisSession.getScopeSessionFor(firSession))

        return samResolver.getSamConstructor(fir)?.symbol
    }

    /**
     * Finds constructors with a given [targetClassName] available within the [scope], including SAM constructors
     * (which are not explicitly declared in the class).
     *

     */
    private fun FirNamedReference.getCorrespondingTypeIfPossible(): ConeKotlinType? =
        findOuterPropertyAccessExpression()?.resolvedType

    /**
     * Finds an outer expression for [this] named reference in cases when it is a part of a property access.
     *
     * Otherwise, return null.
     */