=back
+=item mac_addr_formatted CASE DELIMITER
+
+Format the MAC address (for use by exports). If CASE starts with "l"
+(for "lowercase"), it's returned in lowercase. DELIMITER is inserted
+between octets.
+
+=cut
+
+sub mac_addr_formatted {
+ my $self = shift;
+ my ($case, $delim) = @_;
+ my $addr = $self->mac_addr;
+ $addr = lc($addr) if $case =~ /^l/i;
+ join( $delim || '', $addr =~ /../g );
+}
+
+=back
+
+
#class method
sub _upgrade_data {
my $class = shift;