<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def groups(self):
 """Return the names of groups in the file Note that there is not necessarily a TDMS object associated with each group name. :rtype: List of strings. """


        # Split paths into components and take the first (group) component.
        object_paths = (
            path_components(path)
            for path in self.objects)
        group_names = (path[0] for path in object_paths if len(path) > 0)

        # Use an ordered dict as an ordered set to find unique
        # groups in order.
        groups_set = OrderedDict()
        for group in group_names:
            groups_set[group] = None
        return list(groups_set)