Bug 265425 [Workbench] Finalize API for Platform constants in org.eclipse.jface.util.Util
bundles/org.eclipse.jface/src/org/eclipse/jface/util/Util.java
/**
	 * An unmodifiable, empty, sorted set. This value is guaranteed to never
	 * change and never be <code>null</code>.
	 */
	public static final SortedSet EMPTY_SORTED_SET = Collections
			.unmodifiableSortedSet(new TreeSet());
	/**
	 * A common zero-length string. It avoids needing write <code>NON-NLS</code>
	 * next to code fragments. It's also a bit clearer to read.
	 */
	public static final String ZERO_LENGTH_STRING = ""; 
	/**
	 * Verifies that the given object is an instance of the given class.
	 * 
	 * @param object
	 *            The object to check; may be <code>null</code>.
	 * @param c
	 *            The class which the object should be; must not be
	 *            <code>null</code>.
	 */
	public static final void assertInstance(final Object object, final Class c) {
		assertInstance(object, c, false);