std::set<ExportTimespanPtr> timespan_set;
for (ConfigMap::iterator it = config_map.begin(); it != config_map.end(); ++it) {
timespan_set.insert (it->first);
std::set<ExportTimespanPtr> timespan_set;
for (ConfigMap::iterator it = config_map.begin(); it != config_map.end(); ++it) {
timespan_set.insert (it->first);