Bug 29853 [Workbench] OpenWithMenu and setFile
The constructor that only takes the IWorkbenchPage mentions that the user must use the setFile method...this method does not exist.
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/actions/OpenWithMenu.java
private IWorkbenchPage page;
    private IAdaptable file;
    private IEditorRegistry registry = PlatformUI.getWorkbench()
            .getEditorRegistry();
    private static Hashtable imageCache = new Hashtable(11);
    /**
     * The id of this action.
     */
    public static final String ID = PlatformUI.PLUGIN_ID + ".OpenWithMenu";
    /**
     * Match both the input and id, so that different types of editor can be opened on the same input.
     */
    private static final int MATCH_BOTH = IWorkbenchPage.MATCH_INPUT | IWorkbenchPage.MATCH_ID;
    
    /*
     * Compares the labels from two IEditorDescriptor objects 
     */
    private static final Comparator comparer = new Comparator() {
        private Collator collator = Collator.getInstance();
        public int compare(Object arg0, Object arg1) {
            String s1 = ((IEditorDescriptor) arg0).getLabel();
            String s2 = ((IEditorDescriptor) arg1).getLabel();
            return collator.compare(s1, s2);
        }
    };
    /**
     * Constructs a new instance of <code>OpenWithMenu</code>.