Bug 41743 [MenuMgmt] IContributionManager.remove has undocumented behavior
build 20030820 The doc for IContributionManager.remove says that null will be returned if "this manager has no contribution items with the given id". When I call remove on a menu with an invalid ID I get an IllegalArgumentException instead of a null return value.
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ContributionManager.java
*/
protected boolean allowItem(IContributionItem itemToAdd) {
    return true;
}
/**
 * Internal debug method for printing statistics about this manager
 * to <code>System.out</code>.
 */
protected void dumpStatistics() {
	int size= 0;
	if (contributions != null)
		size = contributions.size();
		
	System.out.println(this.toString());
	System.out.println("   Number of elements: " + size);
	int sum= 0;
	for (int i= 0; i < size; i++)
		if (((IContributionItem) contributions.get(i)).isVisible())
			sum++;
	System.out.println("   Number of visible elements: " + sum);
	System.out.println("   Is dirty: " + isDirty());				
}
/* (non-Javadoc)
 * Method declared on IContributionManager.
 */
public IContributionItem find(String id) {
	Iterator e= contributions.iterator();
	while (e.hasNext()) {
		IContributionItem item= (IContributionItem) e.next();
		String itemId= item.getId();