def __unique_trace_events__(trace_events):
    """
    Finds unique trace events.

    :param trace_events: Events found in the trace (filtered by family).
    :return: Unique trace events
    """
    unique_events = {}
    for line in trace_events:
        if line[0] not in unique_events.keys():
            unique_events[line[0]] = [line[1]]
        else:
            if line[1] not in unique_events[line[0]]:
                unique_events[line[0]].append(line[1])
    return unique_events