The context parameter can be used to extract additional information about the environment from which this converter is being invoked. This can be nullNothingnullptra null reference (Nothing in Visual Basic), so always check. Also, properties on the context object can return nullNothingnullptra null reference (Nothing in Visual Basic).
Depending on the implementation of the value formatter, it might be possible to pass the returned string back into the value formatter to re-create an instance of the object.