The current OpenWikiPage reference page is quite outdated and does not reflect changes made to the API. In version 392, the Context Help widget was removed in favor of opening wiki pages in an external browser. However, the documentation does not reflect this change which may result in a new plugin developer being confused about the different behavior when calling the function.
In addition, to being outdated, at the top of the page, it says url links to."> due to a malformed meta tag.