#!/usr/bin/perl -w
use strict;
use diagnostics;
use warnings FATAL => 'all';
use Data::Dumper;
$Data::Dumper::Useperl = 1;
$Data::Dumper::Indent = 1;
$Data::Dumper::Sortkeys = 1;
$Data::Dumper::Useqq = 1;
$Data::Dumper::Deparse = 1;
use Params::Validate qw(:all);

sub foo {
  validate(
    @_,
    { 'bar' => 1, # mandatory
      'baz' => 0, # optional
    }
  );
  print "Hello Nurse!\n";
}
foo('bar' => "arg1");

sub qux {
  validate(
    @_,
    {}
  );
  print "Empty Hash\n";
}
qux('test');