Imagine using PDL::Graphics::Prima::Simple as...

gistfile1.pl

use strict;
use warnings;

sub my_plot {
    croak("Expected key/value pairs, but got an odd number of arguments to pot()")
        if @_ % 2 == 1;
    print "About to plot!\n";
    PDL::Graphics::Prima::Simple::default_plot(@_);
}

use PDL::Graphics::Prima::Simple plot => \&my_plot;