How to use the pymtp.LIBMTP_MTPDevice function in PyMTP

("FreeSpaceInObjects", ctypes.c_uint64),
                                 ("StorageDescription", ctypes.c_char_p),
                                 ("VolumeIdentifier", ctypes.c_char_p),
                                 ("next", ctypes.POINTER(LIBMTP_DeviceStorage)),
                                 ("prev", ctypes.POINTER(LIBMTP_DeviceStorage))]

class LIBMTP_MTPDevice(ctypes.Structure):
	"""
		LIBMTP_MTPDevice
		Contains the ctypes structure for LIBMTP_mtpdevice_t
	"""

	def __repr__(self):
		return self.interface_number

LIBMTP_MTPDevice._fields_ = [("interface_number", ctypes.c_uint8),
                             ("params", ctypes.c_void_p),
                             ("usbinfo", ctypes.c_void_p),
                             ("storage", ctypes.POINTER(LIBMTP_DeviceStorage)),
                             ("errorstack", ctypes.POINTER(LIBMTP_Error)),
                             ("maximum_battery_level", ctypes.c_uint8),
                             ("default_music_folder", ctypes.c_uint32),
                             ("default_playlist_folder", ctypes.c_uint32),
                             ("default_picture_folder", ctypes.c_uint32),
                             ("default_video_folder", ctypes.c_uint32),
                             ("default_organizer_folder", ctypes.c_uint32),
                             ("default_zencast_folder", ctypes.c_uint32),
                             ("default_album_folder", ctypes.c_uint32),
                             ("default_text_folder", ctypes.c_uint32),
                             ("cd", ctypes.c_void_p),
                             ("next", ctypes.POINTER(LIBMTP_MTPDevice))]

# ----------
# Type Definitions
# ----------
 
_libmtp.LIBMTP_Get_Friendlyname.restype = ctypes.c_char_p
_libmtp.LIBMTP_Get_Serialnumber.restype = ctypes.c_char_p
_libmtp.LIBMTP_Get_Modelname.restype = ctypes.c_char_p
_libmtp.LIBMTP_Get_Manufacturername.restype = ctypes.c_char_p
_libmtp.LIBMTP_Get_Deviceversion.restype = ctypes.c_char_p
_libmtp.LIBMTP_Get_Filelisting_With_Callback.restype = ctypes.POINTER(LIBMTP_File)
_libmtp.LIBMTP_Get_Tracklisting_With_Callback.restype = ctypes.POINTER(LIBMTP_Track)
_libmtp.LIBMTP_Get_Filetype_Description.restype = ctypes.c_char_p
_libmtp.LIBMTP_Get_Filemetadata.restype = ctypes.POINTER(LIBMTP_File)
_libmtp.LIBMTP_Get_Trackmetadata.restype = ctypes.POINTER(LIBMTP_Track)
_libmtp.LIBMTP_Get_First_Device.restype = ctypes.POINTER(LIBMTP_MTPDevice)
_libmtp.LIBMTP_Get_Playlist_List.restype = ctypes.POINTER(LIBMTP_Playlist)
_libmtp.LIBMTP_Get_Playlist.restype = ctypes.POINTER(LIBMTP_Playlist)
_libmtp.LIBMTP_Get_Folder_List.restype = ctypes.POINTER(LIBMTP_Folder)
_libmtp.LIBMTP_Find_Folder.restype = ctypes.POINTER(LIBMTP_Folder)
_libmtp.LIBMTP_Get_Errorstack.restype = ctypes.POINTER(LIBMTP_Error)
# This is for callbacks with the type of LIBMTP_progressfunc_t
Progressfunc = ctypes.CFUNCTYPE(ctypes.c_void_p, ctypes.c_uint64, ctypes.c_uint64)

# ----------
# End Type Definitions
# ----------

class MTP:
	"""
		The MTP object 
		This is the main wrapper around libmtp