code: function() {
        this.threadsByLinuxPid = {};
        this.model_.getAllThreads().forEach(
            function(thread) {
              this.threadsByLinuxPid[thread.tid] = thread;
            }.bind(this));
      }
docs: Precomputes a lookup table from linux pids back to existing
  Threads. This is used during importing to add information to each
  thread about whether it was running, descheduled, sleeping, et
  cetera.