What needs to be considered to ensure the proper functioning of the TreeSet data structure?

For the proper functioning of the TreeSet data structure in Java, the following should be considered:

• Elements must be comparable: TreeSet stores elements in sorted order, so objects should implement the Comparable interface or a Comparator should be provided when creating the TreeSet.
• Consistency of comparison: the implementation of compareTo (or Comparator) should be consistent with equals to avoid unpredictable behavior.
• Immutability of elements after addition: if elements are modified in a way that changes their order, it will break the TreeSet structure.

Example of creating a TreeSet with a Comparator:

TreeSet<String> set = new TreeSet<>(Comparator.naturalOrder());
set.add("apple");
set.add("banana");
set.add("cherry");