def __create_context(self, main_root):
		context_dir = os.path.join(main_root, 'context')
		safe_mkdir(context_dir)

		action_default = {}
		for unit, param in self.__task.data['workflow'].items():
			action_default[unit] = self.__action_mgr.default_config(param['type'])

		navigators = self.__config_mgr.navigator()
		context_format = self.__navigator_mgr.context_format(navigators)

		self.__context_mgr.create_context_file(self.__task.data, action_default, context_format, context_dir)
def __getitem__(self, index):
        """Return example at given index.

        Args:
            index(int): The index of the example to retrieve

        Returns:
            tuple: A 3-tuple with ``(img1, img2, flow)``.
            The flow is a numpy array of shape (2, H, W) and the images are PIL images.
            ``flow`` is None if ``split="test"``.
            If a valid flow mask is generated within the ``transforms`` parameter,
            a 4-tuple with ``(img1, img2, flow, valid_flow_mask)`` is returned.
        """
        return super().__getitem__(index)