Bug 329930 Resetting a perspective while its active part is not defined in the perspective causes the perspective to not have an active part after the reset
1. Window > Show View > Console 2. Window > Reset Perspective... > OK 3. No parts are active.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/workbench/modeling/EPartService.java
* <li>If <code>CREATE</code> is supplied, then the part will be instantiated though its
	 * contents may not necessarily be visible to the end user. visible to the end user.</li>
	 * </ul>
	 * </p>
	 * 
	 * @param part
	 *            the part to show
	 * @param partState
	 *            the desired state of the shown part to be in
	 * @return the shown part
	 */
	public MPart showPart(MPart part, PartState partState);
	/**
	 * Hides the given part. The part must be a part managed by this service.
	 * <p>
	 * If the part has been tagged with the {@link #REMOVE_ON_HIDE_TAG} tag, it will be removed from
	 * the model when the service hides it.
	 * </p>
	 * 
	 * @param part
	 *            the part to hide
	 */
	public void hidePart(MPart part);
	/**
	 * Hides the given part. The part must be a part managed by this service.
	 * <p>
	 * If <code>force</code> is <code>true</code> or the part has been tagged with the
	 * {@link #REMOVE_ON_HIDE_TAG} tag, it will be removed from the model when the service hides it.
	 * </p>
	 *