+Returns a "masked" payinfo field with all but the last four characters replaced
+by 'x'es. Useful for displaying credit cards.
+
+=cut
+
+sub payinfo_masked {
+ my $self = shift;
+ my $payinfo = $self->payinfo;
+ 'x'x(length($payinfo)-4). substr($payinfo,(length($payinfo)-4));
+}
+
+=back