(self, master_callback)
Args:
            master_callback: a callback to be invoked after having collected messages from slave devices.
def __init__(self, master_callback):
        """

        Args:
            master_callback: a callback to be invoked after having collected messages from slave devices.
        """
        self._master_callback = master_callback
        self._queue = queue.Queue()
        self._registry = collections.OrderedDict()
        self._activated = False
def __init__ ( self , master_callback ) : self . _master_callback = master_callback self . _queue = queue . Queue ( ) self . _registry = collections . OrderedDict ( ) self . _activated = False