code: def add(device_id, host, adbkey='', adb_server_ip='', adb_server_port=5037):
      
      valid = is_valid_device_id(device_id) and is_valid_host(host)
      if valid:
          devices[device_id] = FireTV(str(host), str(adbkey), str(adb_server_ip), str(adb_server_port))
      return valid
docs: Add a device.
  
      Creates FireTV instance associated with device identifier.
  
      :param device_id: Device identifier.
      :param host: Host in <address>:<port> format.
      :param adbkey: The path to the "adbkey" file
      :param adb_server_ip: the IP address for the ADB server
      :param adb_server_port: the port for the ADB server
      :returns: Added successfully or not.