docs: def to_vobject(self, filename=None, uid=None):
          """Return iCal object of Remind lines
          If filename and UID are specified, the vObject only contains that event.
          If only a filename is specified, the vObject contains all events in the file.
          Otherwise the vObject contains all all objects of all files associated with the Remind object.
  
          filename -- the remind file
          uid -- the UID of the Remind line
          """
          self._update()
  
          cal = iCalendar()
          if uid:
              self._gen_vevent(self._reminders[filename][uid], cal.add('vevent'))
          elif filename:
              for event in self._reminders[filename].values():
                  self._gen_vevent(event, cal.add('vevent'))
          else:
              for filename in self._reminders:
                  for event in self._reminders[filename].values():
                      self._gen_vevent(event, cal.add('vevent'))
          return cal