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
*
     * @param newImage the image, or <code>null</code> if this 
     *   action should not have an image
     * @see #IMAGE
     */
    public void setHoverImageDescriptor(ImageDescriptor newImage);
    /**
     * Sets the unique identifier for this action. This is used to identify actions
     * when added to a contribution manager.
     * It should be set when the action is created.  It should not be modified once
     * the action is part of an action contribution item.
     *
     * @param id the action id
     *
     * @see ActionContributionItem
     * @see IContributionItem#getId
     */
    public void setId(String id);
    /**
     * Sets the image for this action, as an image descriptor.
     * <p>
     * Fires a property change event for the <code>IMAGE</code> property
     * if the image actually changes as a consequence.
     * </p>
     *
     * @param newImage the image, or <code>null</code> if this 
     *   action should not have an image
     * @see #IMAGE
     */
    public void setImageDescriptor(ImageDescriptor newImage);