Bug 88352 Operation supports leaks contexts via action handler
I20050315-1100 Susan, this is a different leak from the one that I reported. Test Case: 1. open text editor 2. close text editor ==> DefaultUndoManager is leaked due to undo/redo actions handlers still holding on to the context.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/ObjectUndoContext.java
*/
	public void addMatch(IUndoContext context) {
		children.add(context);
	}
	/**
	 * Remove the specified context as a match of this context. The context will
	 * no longer be interpreted as a match of this context when the history is
	 * filtered for a particular context. This method has no effect if the
	 * specified context was never previously added as a match.
	 * 
	 * @param context -
	 *            the context to be removed from the list of matches for this
	 *            context
	 */
	public void removeMatch(IUndoContext context) {
		children.remove(context);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IUndoContext#matches(IUndoContext
	 *      context)
	 */
	public boolean matches(IUndoContext context) {
		if (children.contains(context))
			return true;
		return super.matches(context);
	}
}