'Init the EM object.
:param self: An ExtensionManager object
:type self: ExtensionManager
:return: None
:rtype: None'

def __init__(self, network_manager):

    self._nm = network_manager
    self._extensions_str = []
    self._extensions = []
    self._interface = None
    self._socket = None
    self._should_continue = True
    self._packets_to_send = {str(k): [] for k in range(1, 14)}
    self._packets_to_send['*'] = []
    self._channels_to_hop = []
    self._current_channel = '1'
    self._listen_thread = threading.Thread(target=self._listen)
    self._send_thread = threading.Thread(target=self._send)
    self._channelhop_thread = threading.Thread(target=self._channel_hop)
