How to use the mobly.controllers.android_device_lib.adb.AdbProxy function in mobly

def list_adb_devices_by_usb_id():
    """List the usb id of all android devices connected to the computer that
    are detected by adb.

    Returns:
        A list of strings that are android device usb ids. Empty if there's
        none.
    """
    out = adb.AdbProxy().devices(['-l'])
    clean_lines = new_str(out, 'utf-8').strip().split('\n')
    results = []
    for line in clean_lines:
        tokens = line.strip().split()
        if len(tokens) > 2 and tokens[1] == 'device':
            results.append(tokens[2])
    return results

def list_occupied_adb_ports():
    """Lists all the host ports occupied by adb forward.

    This is useful because adb will silently override the binding if an attempt
    to bind to a port already used by adb was made, instead of throwing binding
    error. So one should always check what ports adb is using before trying to
    bind to a port with adb.

    Returns:
        A list of integers representing occupied host ports.
    """
    out = AdbProxy().forward('--list')
    clean_lines = str(out, 'utf-8').strip().split('\n')
    used_ports = []
    for line in clean_lines:
        tokens = line.split(' tcp:')
        if len(tokens) != 3:
            continue
        used_ports.append(int(tokens[1]))
    return used_ports

def __init__(self, serial=''):
        self._serial = str(serial)
        # logging.log_path only exists when this is used in an Mobly test run.
        self._log_path_base = getattr(logging, 'log_path', '/tmp/logs')
        self._log_path = os.path.join(
            self._log_path_base, 'AndroidDevice%s' % self._normalized_serial)
        self._debug_tag = self._serial
        self.log = AndroidDeviceLoggerAdapter(logging.getLogger(),
                                              {'tag': self.debug_tag})
        self._build_info = None
        self._is_rebooting = False
        self.adb = adb.AdbProxy(serial)
        self.fastboot = fastboot.FastbootProxy(serial)
        if self.is_rootable:
            self.root_adb()
        self.services = service_manager.ServiceManager(self)
        self.services.register(SERVICE_NAME_LOGCAT,
                               logcat.Logcat,
                               start_service=False)
        self.services.register(
            'snippets', snippet_management_service.SnippetManagementService)
        # Device info cache.
        self._user_added_device_info = {}

def list_adb_devices():
    """List all android devices connected to the computer that are detected by
    adb.

    Returns:
        A list of android device serials. Empty if there's none.
    """
    out = adb.AdbProxy().devices()
    return parse_device_list(out, 'device')