Bug 251257 [Contributions] IAction.setImageDescriptor() javadoc needs to note "image vs. checked" platform discrepancy
bundles/org.eclipse.jface/src/org/eclipse/jface/action/IAction.java
* and a key, as explained in <code>MenuItem.getAccelerator</code>.
     *
     * @return the accelerator keycode
     * @see org.eclipse.swt.widgets.MenuItem#getAccelerator()
     */
    public int getAccelerator();
    /**
     * Returns the action definition id of this action.
     * 
     * @return the action definition id of this action, or
     * <code>null</code> if none
     * @since 2.0
     */
    public String getActionDefinitionId();
    /**
     * Returns the action's description if it has one.
     * Otherwise it returns <code>getToolTipText()</code>.
     * 
     * @return a description for the action; may be <code>null</code> 
     */
    public String getDescription();
    /**
     * Returns the disabled image for this action as an image descriptor.
     * <p>
     * This method is associated with the <code>IMAGE</code> property;
     * property change events are reported when its value changes.
     * </p>
     *
     * @return the image, or <code>null</code> if this action has no image
     * @see #IMAGE