undefined method `size' for nil:NilClass
../chartutil.rb:15 ../chartutil.rb:122:in `[]' ../chartutil.rb:122:in `time_hist_chart' ./google_chart/line_chart.rb:32:in `initialize' ../chartutil.rb:98:in `new' ../chartutil.rb:98:in `time_hist_chart' /home/i/wrk/cia/site/index.cgi:63 /usr/lib/ruby/1.8/pstore.rb:322:in `transaction' /usr/lib/ruby/1.8/pstore.rb:321:in `catch' /usr/lib/ruby/1.8/pstore.rb:321:in `transaction' /home/i/wrk/cia/site/index.cgi:59