getExistingLink(String path, Document document) Returns a link of a certain node, preferably in the document's language,
or null if the node has no links.
Parameters: path - The path of the node. Parameters: document - The document.
Returns a link of a certain node, preferably in the document's language,
or null if the node has no links.
Parameters: path - The path of the node. Parameters: document - The document. A link or null. throws: SiteException - if an error occurs.