* Subtitle::SSA::* : add get_format_line() helper

lib/Subtitle/SSA/Record.pm

@@ -121,4 +121,15 @@ sub to_string {
   return $string;
 }
 
+sub get_format_line {
+  my ($self) = @_;
+
+  my @keys  = @{ $self->{_format} };
+  my @names = map { $FIELDS{$_}->{name} } @keys;
+
+  my $line = 'Format: ' . join(', ' => @names);
+
+  return $line;
+}
+
 1;