How to use the eventkit.ops.combine.JoinOp.__init__ function in eventkit

def __init__(self, *sources: Event):
        JoinOp.__init__(self)
        self._sources = deque()
        self._parent = None
        self._set_sources(*sources)

def __init__(self, *sources):
        JoinOp.__init__(self)
        self._num_ready = 0  # number of sources with a pending result
        self._source2cbs = defaultdict(list)  # map from source to callbacks
        if sources:
            self._set_sources(*sources)

def __init__(self, *sources, partial=True):
        JoinOp.__init__(self)
        self._is_primed = partial
        self._source2cbs = defaultdict(list)  # map from source to callbacks
        if sources:
            self._set_sources(*sources)