How to use the pymtp.LIBMTP_File function in PyMTP

("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))]

class LIBMTP_File(ctypes.Structure):
	"""
		LIBMTP_File
		Contains the ctypes structure for LIBMTP_file_t
	"""

	def __repr__(self):
		return "%s (%s)" % (self.filename, self.item_id)

LIBMTP_File._fields_ = [("item_id", ctypes.c_uint32),
                        ("parent_id", ctypes.c_uint32),
                        ("storage_id", ctypes.c_uint32),
                        ("filename", ctypes.c_char_p),
                        ("filesize", ctypes.c_uint64),
			("filetype", ctypes.c_int),
			("next", ctypes.POINTER(LIBMTP_File))]

class LIBMTP_Track(ctypes.Structure):
	"""
		LIBMTP_Track
		Contains the ctypes structure for LIBMTP_track_t
	"""

	def __repr__(self):
		return "%s - %s (%s)" % (self.artist, self.title, self.item_id)

# End Data Model Definitions
# ----------

# ----------
# 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:
	"""

receive callbacks from ptp. Callback function must
			 take two arguments, sent and total (in bytes)
			@rtype: int
			@return: The object ID of the new file
		"""

		if (self.device == None):
			raise NotConnected

		if (os.path.isfile(source) == False):
			raise IOError
			
		if (callback != None):
			callback = Progressfunc(callback)

		metadata = LIBMTP_File(filename=target, \
		  filetype=self.find_filetype(source), \
		  filesize=os.stat(source).st_size)

		ret = self.mtp.LIBMTP_Send_File_From_File(self.device, source, \
		  ctypes.pointer(metadata), callback, None, parent)

		if (ret != 0):
			self.debug_stack()
			raise CommandFailed

		return metadata.item_id