# from Text/PDF/Filter.pm

package Text::PDF::FlateDecode;

use strict;
use vars qw(@ISA $havezlib);
@ISA = qw(Text::PDF::Filter);
BEGIN
{
    eval {require "Compress/Zlib.pm";};
    $havezlib = !$@;
}

sub new
{
    return undef unless $havezlib;
    my ($class) = @_;
    my ($self) = {};

    $self->{'outfilt'} = Compress::Zlib::deflateInit();
    $self->{'infilt'} = Compress::Zlib::inflateInit();
    bless $self, $class;
}

##</code><code>##

sub encodeOne  ## no critic(Subroutines::ProhibitExcessComplexity)
{
   my $self = shift;
   my $objnode = shift;
   my $filtername = shift;

   (...)

      my $filt;
      eval {
         require Text::PDF::Filter;
         my $package = "Text::PDF::$filtername";
         $filt = $package->new;
         if (!$filt)
         {
            die;
         }
      };
      if ($EVAL_ERROR)
      {
         warn "Failed to open filter $filtername (Text::PDF::$filtername)\n";
         return 0;
      }
   (...)