Constructs a new, empty tree set, sorted according to the
natural ordering of its elements. All elements inserted into
the set must implement the {@link Comparable} interface.
Furthermore, all such elements must be <i>mutually
comparable</i>: {@code e1.compareTo(e2)} must not throw a
{@code ClassCastException} for any elements {@code e1} and
{@code e2} in the set. If the user attempts to add an element
to the set that violates this constraint (for example, the user
attempts to add a string element to a set whose elements are
integers), the {@code add} call will throw a
{@code ClassCastException}.
Constructs a new, empty tree set, sorted according to the natural ordering of its elements. All elements inserted into the set must implement the {@link Comparable} interface. Furthermore, all such elements must be <i>mutually comparable</i>: {@code e1.compareTo(e2)} must not throw a {@code ClassCastException} for any elements {@code e1} and {@code e2} in the set. If the user attempts to add an element to the set that violates this constraint (for example, the user attempts to add a string element to a set whose elements are integers), the {@code add} call will throw a {@code ClassCastException}.