bool NumericIndivProvider::get_variables_map(variables_map &oMap) {
	assert(this->is_valid());
	oMap.clear();
	variables_map vars;
	if (!this->m_provider->get_variables_map(vars)) {
		return (false);
	}
	const statinfos_map &filter = this->m_stats;
	typedef std::pair<IntType, DBStatVariable> MyPair;
	std::for_each(vars.begin(), vars.end(), [&](const MyPair &oPair) {
		const IntType key = oPair.first;
		if (filter.find(key) != filter.end()) {
			oMap[key] = oPair.second;
		} // ok
		});
	return (true);
}