+=head2 C<filter>
+
+ my $filtered_report = $tvt->filter($session, $report);
+
+The C<$session> calls this method after receiving a report from the parser and before letting the command filter it.
+You can either return a mangled C<$report> (which does not need to be a clone of the original) or C<undef> if you want the action to ignore it completely.
+
+Defaults to the identity function.
+
+=cut
+
+sub filter { $_[2] }
+
+=head2 C<finish>
+
+ $tvt->finish($session);