void (String[] args) { Collection unmodifiableCollection = Collections.unmodifiableCollecti<caret>on(getEmptyList()); List unmodifiableList = Collections.unmodifiableList(getEmptyList()); Set unmodifiableSet = Collections.unmodifiableSet(getEmptySet()); Map unmodifiableMap = Collections.unmodifiableMap(getEmptyMap()); SortedSet unmodifiableSortedSet = Collections.unmodifiableSortedSet(getEmptySet()); SortedMap unmodifiableSortedMap = Collections.unmodifiableSortedMap(getEmptyMap()); NavigableSet unmodifiableNavigableSet = Collections.unmodifiableNavigableSet(getEmptySet()); NavigableMap unmodifiableNavigableMap = Collections.unmodifiableNavigableMap(getEmptyMap()); }