+sub _validate_pkg {
+ my ($pkg, $cur) = @_;
+ return $cur unless $pkg;
+ 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 =~ /^::/;
+ $pkg;
+}
+