+# Set to non-undef to pick out one specific game from a PGN file with many games.
+# See example.
+our $pgn_filter = undef;
+#our $pgn_filter = sub {
+# my $pgn = shift;
+# return $pgn->round() eq '7' && $pgn->white eq 'Carlsen,M';
+#};
+
+# Set to non-undef to override the clock information with our own calculations.
+# The example implements a simple 60+60 (with bonus added before the move).
+# FIXME(sesse): We might not see all moves in a PGN individually, so this might
+# skip some moves for bonus.
+our $adjust_clocks_before_move = undef;
+#our $adjust_clocks_before_move = sub {
+# my ($white_clock_left, $black_clock_left, $move, $toplay) = @_;
+#
+# if (!defined($$white_clock_left) || !defined($$black_clock_left)) {
+# $$white_clock_left = 3600;
+# $$black_clock_left = 3600;
+# }
+# if ($toplay eq 'W') {
+# $$white_clock_left += 60;
+# } else {
+# $$black_clock_left += 60;
+# }
+#};
+