s</p></dd><dt class="param">lookback</dt><dd class="cmt"><p>The parameter that describes the maximum time difference that two events can have in order to
                    create an event type pair.</p></dd><dt>returns</dt><dd class="cmt"><p>Two RDDs: (1) The first one that contains all the extracted event type pairs and (2) the second one contains
        the last timestamp of each event type pair for each trace.</p></dd></dl></div>
    </li><li name="scala.AnyRef#getClass" visbl="pub" class="indented0 "