/**
* Adds an element to the list if it is not already present.
*
* <p><i>(Violation)</i> The <code>List</code> interface requires that this method returns <code>
* true</code> always. However this class may return <code>false</code> because of the <code>Set
* </code> behaviour.
*
* @param object the object to add
* @return true if object was added
*/
@Override
public boolean add(final E object) {
// gets initial size
final int sizeBefore = size();
// adds element if unique
add(size(), object);
// compares sizes to detect if collection changed
return sizeBefore != size();
}
