32   serial = kwargs.get('serial', None)
34   if serial:
35     prefix += ['-s', serial]
71 def ensure_single_device(serial):  argument
73   if serial is None and len(serials) == 1:
76   if serial in serials:
77     return serial
81   elif serial is None:
84     print('No device with serial {} found.'.format(serial))
88 def pull_format_files(serial, output_directory):  argument
99   output = adb('shell', cmd, serial=serial)
112 def get_output_directory(prefix=None, serial=None):  argument
113   build_id = adb('shell', 'getprop', 'ro.build.id', serial=serial).strip()
114   product = adb('shell', 'getprop', 'ro.build.product', serial=serial).strip()
115   kernel = adb('shell', 'uname', '-r', serial=serial).split('-')[0].strip()
131   serial = args.serial
133   serial = ensure_single_device(serial)
134   output_directory = get_output_directory(prefix, serial)
137   pull_format_files(serial, output_directory)