+ shift;
+ croak 'Optional arguments must be passed as keys/values pairs' if @_ % 2;
+ my %args = @_;
+ my $cur = (caller 1)[0];
+ my $pkg;
+ if ($pkg = $args{in}) {
+ croak 'Invalid package name' if ref $pkg
+ or $pkg =~ /(?:-|[^\w:])/
+ or $pkg =~ /(?:\A\d|\b:(?::\d|(?:::+)?\b))/;
+ $pkg =~ s/::$//;
+ $pkg = $cur . $pkg if $pkg eq '' or $pkg =~ /^::/;
+ } else {
+ $pkg = $cur;
+ }