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
if (itemId != null && itemId.equalsIgnoreCase(id))
			return item;
	}
	return null;
}
/* (non-Javadoc)
 * Method declared on IContributionManager.
 */
public IContributionItem[] getItems() {
	IContributionItem[] items = new IContributionItem[contributions.size()];
	contributions.toArray(items);
	return items;
}
/**
 * The <code>ContributionManager</code> implementation of this
 * method declared on <code>IContributionManager</code> returns
 * the current overrides. If there is no overrides it lazily creates
 * one which overrides no item state.
 * 
 * @since 2.0
 */
public IContributionManagerOverrides getOverrides() {
	if (overrides == null) {
		overrides = new IContributionManagerOverrides() {
			public Boolean getEnabled(IContributionItem item) {
				return null;
			}
			public Integer getAccelerator(IContributionItem item) {
				return null;
			}