+=item clone
+
+Creates a new billing item definition by duplicating an existing definition.
+A new pkgpart is assigned and "(CUSTOM) " is prepended to the comment field.
+
+=cut
+
+sub clone {
+ my $self = shift;
+ my %hash = $self->hash;
+ $hash{'comment'} = "(CUSTOM) ". $hash{'comment'}
+ unless $hash{'comment'} =~ /^\(CUSTOM\) /;
+ create ( { $self->hash } );
+}
+