Gets the class of the destination page, which serves as a form of identity that can be used
to determine if a link is on the same Page that it links to. When Pages are parameterized,
the Link.linksTo() method should be overridden instead.
A page's identity is important because links which are on the same page that they link to
often need to be displayed in a different way to indicate that they are 'disabled' and don't
go anywhere. Links can be manually disabled by calling Link.setDisabled(). Links which have
setAutoEnable(true) will automatically enable or disable themselves depending on whether or
not Link.linksTo() returns true. The default implementation of PageLink.linksTo() therefore
looks like this:
private final IPageLink pageLink;
public boolean linksTo(final Page page)
{
return page.getClass() == pageLink.getPageIdentity();
}