*
     * [computePackageNames] is used as the default implementation for [computePackageNamesWithTopLevelClassifiers] and
     * [computePackageNamesWithTopLevelCallables] if either returns `null`. It depends on the declaration provider whether it's worth
     * computing separate package sets for classifiers and callables, or just one set containing all package names.
     */

        get() = providers.any { it.hasSpecificCallablePackageNamesComputation }

    override fun computePackageNamesWithTopLevelCallables(): Set<String>? {
        return providers.flatMapToNullableSet { it.computePackageNamesWithTopLevelCallables() }
    }

    public companion object {

        buildPackageNamesSetFrom(index.classMap.keys, index.typeAliasMap.keys)

    override val hasSpecificCallablePackageNamesComputation: Boolean get() = true

    override fun computePackageNamesWithTopLevelCallables(): Set<String> =
        buildPackageNamesSetFrom(index.topLevelPropertyMap.keys, index.topLevelFunctionMap.keys)

    @Suppress("NOTHING_TO_INLINE")