DescribeSecurityGroupsType sgt = describeSecurityGroups.getDescribeSecurityGroups();
FilterSetType fst = sgt.getFilterSet();
// -> toEC2DescribeSecurityGroups
DescribeSecurityGroupsSetType sgst = sgt.getSecurityGroupSet();
DescribeSecurityGroupsSetItemType[] items = sgst.getItem();
if (null != items) { // -> can be empty
for (DescribeSecurityGroupsSetItemType item : items)
request.addGroupName(item.getGroupName());
}