def get_corresponding_trail(path):
    """Given a path in the line graph of a directed graph, returns the trail in
    the directed graph corresponding to the path.

    :param path: path in a line graph of a directed graph
    :return: the trail in the directed graph corresponding to the path in the
        line graph
    """
    trail = list()

    if len(path) > 0:
        trail = list(path[0])
        for arc in path[1:]:
            trail.append(arc[1])

    return trail