> perl
print "Data::Dumper exists\n" if %Data::Dumper::;
> perl -MData::Dumper
print "Data::Dumper exists\n" if %Data::Dumper::;
Data::Dumper exists

##</code><code>##

if (%HTML::Template::) {
  # HTML::template stuff
} else {
  # Regular HTML stuff
}

##</code><code>##

if (exists ${%HTML::Template::}{'import'}) {
  ...
}