Now i can put all headers like

use 5.010;
use strict;
use warnings;
use Carp;
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in a single header file called "header.pi" and put only one line of code

use Include 'header.pi'
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instead of writing same lines to every file. I can also put my big sub to separate file and say

use Include 'agent.pi'
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where it was originally.

package Include;

use 5.010;
use strict;
use warnings;
use Carp;

use Filter::Util::Call;

sub import 
{
    my (undef, @files) = @_;
    my (undef, $origin, $line) = caller;
    filter_add sub
    {
        filter_del();
        while (defined (my $file = shift(@files)))
        {
            $_ .= "\n# line 1 $file\n";
            local $/;
            undef $!;
            unless (open FH, "<", $file and $_ .= <FH> and !$!)
            {                    
                carp "Can not include '$file':$!";
                return -1;
            }
            close FH;
        }
        ++$line;
        $_ .= "\n# line $line $origin\n";
        return 1;
    };
}
1;
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