def __init__(self):
<EOL>self._transfer_states = {}<EOL>self._id_count = <NUM_LIT:0><EOL>self._init_lock = threading.Lock()<EOL>
Monitors transfers for cross-proccess communication

        Notifications can be sent to the monitor and information can be
        retrieved from the monitor for a particular transfer. This abstraction
        is ran in a ``multiprocessing.managers.BaseManager`` in order to be
        shared across processes.