Bug 53386 [ActivityMgmt] Remove show All from everywhere except new wizards
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
* @see org.eclipse.jface.preference.IPreferencePageContainer#getPreferenceStore()
	 */
	public IPreferenceStore getPreferenceStore() {
		return preferenceStore;
	}
	/**
	 * Get the name of the selected item preference
	 */
	protected String getSelectedNodePreference() {
		return lastPreferenceId;
	}
	/** 
	 * @param selection the <code>ISelection</code> to examine.
	 * @return the first element, or null if empty.
	 */
	protected IPreferenceNode getSingleSelection(ISelection selection) {
		if (!selection.isEmpty())
			return (IPreferenceNode) ((IStructuredSelection) selection).getFirstElement();
		return null;
	}
	/** 
	 * @return the <code>TreeViewer</code> for this dialog.
	 * @since 3.0
	 */
	protected TreeViewer getTreeViewer() {
		return treeViewer;
	}
	/**
	 * Save the values specified in the pages.
	 * <p>