void (String[] args) { Collections unmodifiableCollection = Collections.emptyList(); List unmodifiableList = Collections.emptyList(); Set unmodifiableSet = Collections.emptySet(); Map unmodifiableMap = Collections.emptyMap(); SortedSet unmodifiableSortedSet = Collections.emptySet(); SortedMap unmodifiableSortedMap = Collections.emptyMap(); NavigableSet unmodifiableNavigableSet = Collections.emptySet(); NavigableMap unmodifiableNavigableMap = Collections.emptyMap(); }