packageFqName = packageOrClass.packageFqName
        }
    }

    fun getRegularClass(type: ConeKotlinType?): FirRegularClass? {
        return type?.toRegularClassSymbol(firSession)?.fir
    }

    fun toClassSymbol(classId: ClassId) =
        firSession.symbolProvider.getClassLikeSymbolByClassId(classId)

    fun convertToImportableName(callableSymbol: FirCallableSymbol<*>): FqName? =

            // cannot do so:
            // ```
            // fun x(c: Char) {}
            // fun call(x: kotlin.Int) {
            //   operator fun Int.invoke(a: Int) {}
            //   operator fun Int.invoke(b: Boolean) {}
            //   <expr>x()</expr>
            // }
            // ```