'Reload the configuration.
The result contains three arrays containing names of process
groups:
* `added` gives the process groups that have been added
* `changed` gives the process groups whose contents have
changed
* `removed` gives the process groups that are no longer
in the configuration
@return array result  [[added, changed, removed]]'

def reloadConfig(self):

    self._update('reloadConfig')
    try:
        self.supervisord.options.process_config(do_usage=False)
    except ValueError as msg:
        raise RPCError(Faults.CANT_REREAD, msg)
    (added, changed, removed) = self.supervisord.diff_to_active()
    added = [group.name for group in added]
    changed = [group.name for group in changed]
    removed = [group.name for group in removed]
    return [[added, changed, removed]]
