From Joomla! Documentation
The "API17" namespace is an archived namespace. This page contains information for a Joomla! version which is no longer supported. It exists only as a historical reference, it will not be improved and its content may be incomplete and/or contain broken links.
This class and its methods was never imported into the JDOCs Wiki. Please see the current API for Platform 11.4 - JObservable 11.4