return providers.flatMap { it.getAllClassesByClassId(classId) }
    }

    override fun getAllTypeAliasesByClassId(classId: ClassId): Collection<KtTypeAlias> {
        return providers.flatMap { it.getAllTypeAliasesByClassId(classId) }
    }

    override fun getTopLevelKotlinClassLikeDeclarationNamesInPackage(packageFqName: FqName): Set<Name> {

    override fun getClassLikeDeclarationByClassId(classId: ClassId): KtClassLikeDeclaration? = null
    override fun getAllClassesByClassId(classId: ClassId): List<KtClassOrObject> = emptyList()
    override fun getAllTypeAliasesByClassId(classId: ClassId): List<KtTypeAlias> = emptyList()
    override fun getTopLevelKotlinClassLikeDeclarationNamesInPackage(packageFqName: FqName): Set<Name> = emptySet()

    public abstract fun getClassLikeDeclarationByClassId(classId: ClassId): KtClassLikeDeclaration?

    public abstract fun getAllClassesByClassId(classId: ClassId): Collection<KtClassOrObject>
    public abstract fun getAllTypeAliasesByClassId(classId: ClassId): Collection<KtTypeAlias>

    public abstract fun getTopLevelKotlinClassLikeDeclarationNamesInPackage(packageFqName: FqName): Set<Name>

                        tasks.addLast(Task(newChunks, child))
                    }
                }
            }
        }
    }

    override fun getAllTypeAliasesByClassId(classId: ClassId): Collection<KtTypeAlias> {
        return getClassLikeDeclarationsByClassId(classId).filterIsInstance<KtTypeAlias>().toList()
    }

    override fun getClassLikeDeclarationByClassId(classId: ClassId): KtClassLikeDeclaration? {
        return getAllClassesByClassId(classId).firstOrNull()
            ?: getAllTypeAliasesByClassId(classId).firstOrNull()
    }

    override fun getAllClassesByClassId(classId: ClassId): Collection<KtClassOrObject> =
        index.classMap[classId.packageFqName]
            ?.filter { ktClassOrObject ->