I'm not sure of the wisdom of doing this, but, just for laffs... Two files letssee.pl and Mongo.pm:

---

### letssee.pl
use strict;
use warnings;
use Mongo;

my $buffer = Mongo::payload();

print $buffer;
__END__
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---

### Mongo.pm
use strict;
use warnings;

package Mongo;
use PerlIO::gzip;

1;  # appease require

sub payload {
  binmode( DATA, ':gzip' );
  local $/ = \4096;
  my $ret;
  $ret .= $_ while <DATA>;
  return $ret;
}

__DATA__
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---

Now, append compressed data to Mongo.pm, so that it can be accessed through its DATA handle.

% echo 'hello world'| gzip -c - >> Mongo.pm
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Lastly, run letssee.pl:

% perl letssee.pl
hello world
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The Mongo::payload method reads the compressed payload from the DATA handle, uncompressing it on the fly. See PerlIO and PerlIO::gzip for more details on PerlIO layers.