#!perl use strict; use warnings; use Test::More tests => 2; use VS::Chart; my $chart = VS::Chart->new(); $chart->add(10, 10, 10); $chart->add(20, 20, 20); my $td; $chart->render(type => 'line', as => 'png', to => sub { my ($self, $data) = @_; $td .= $data; }); ok(defined $td); ok(length($td) > 0);