my $conf_file;

    if ( exists $ENV{'CONFIG'} ) {
        $conf_file = $ENV{'CONFIG'};
    }
    elsif ( exists $params->{config} ){
        $config_file = $params->{config};
    }
    else {
        $conf_file = '/usr/local/etc/program.conf'; 
    }

##</code><code>##

my $conf = abs_path( 't/conf/this_test.conf-dist' );
$ENV{'CONFIG'} = $conf;