//check every subreport column, is it in specified subreport or not, and
//if it does, mark it as used
Iterator it = set.iterator();
while(it.hasNext()) {
MathExpressionSubReportColumnRef col = (MathExpressionSubReportColumnRef) it.next();
SubReportColumn val = col.getValue();
if(val.getReport().getReportId() == subReportId) {
used.add(val.getColumnTitle());
}
}
return used;
}