presto-resource-group-managers/src/main/java/io/prestosql/plugin/resourcegroups/db/DbSourceExactMatchSelector.java/DbSourceExactMatchSelector/DbSourceExactMatchSelector
class DbSourceExactMatchSelector:    public DbSourceExactMatchSelector(String environment, ResourceGroupsDao dao)
    {
        this.environment = requireNonNull(environment, "environment is null");
        this.dao = requireNonNull(dao, "dao is null");
    }