Collection charts = (Collection) mmap.get(key);
ArrayList l = new ArrayList(charts);
//Reverse iteration of the charts to meet insertion order
for (int i = l.size(); i > 0; i--) {
DJChart djChart = (DJChart) l.get(i-1);
JRDesignChart chart = createChart(djChart);
//Charts has their own band, so they are added in the band at Y=0
JRDesignBand band = createGroupForChartAndGetBand(djChart);
band.addElement(chart);
}