String region = (String) metadata.get("targetRegion");
String zone = (String) metadata.get("targetZone");
String osName = (String) metadata.get("targetOS");
for (String criteriaName : ImmutableSet.of("iso3166Code", "region", "zone", "osName")) {
MetricCriteria metricCriteria;
String criteriaValue;
if (criteriaName.equals("iso3166Code")) {
criteriaValue = iso3166Code;
metricCriteria = MetricCriteria.ISO_3166_CODE;