public default void remove ()

Removes from the underlying collection the last element returned by this iterator (optional operation). This method can be called only once per call to next. The behavior of an iterator is unspecified if the underlying collection is modified while the iteration is in progress in any way other than by calling this method.

UnsupportedOperationException    if the remove operation is not supported by this iterator
IllegalStateException    if the next method has not yet been called, or the remove method has already been called after the last call to the next method

@implSpec The default implementation throws an instance of UnsupportedOperationException and performs no other action.