public virtual void TestLegacyGetGroupNames()
{
Counters counters = new Counters();
// create 2 filesystem counter groups
counters.FindCounter("fs1", FileSystemCounter.BytesRead).Increment(1);
counters.FindCounter("fs2", FileSystemCounter.BytesRead).Increment(1);
counters.IncrCounter("group1", "counter1", 1);
HashSet <string> groups = new HashSet <string>(((ICollection <string>)counters.GetGroupNames
()));
HashSet <string> expectedGroups = new HashSet <string>();
expectedGroups.AddItem("group1");
expectedGroups.AddItem("FileSystemCounters");
//Legacy Name
expectedGroups.AddItem("org.apache.hadoop.mapreduce.FileSystemCounter");
NUnit.Framework.Assert.AreEqual(expectedGroups, groups);
}