public static void InstanceDataCollection_NullTest()
        {
            InstanceDataCollection idc = GetInstanceDataCollection();

            Assert.Throws <ArgumentNullException>(() => idc[null]);
            Assert.Throws <ArgumentNullException>(() => idc.Contains(null));
        }
        public static void InstanceDataCollection_GetItem_ExistingCounter()
        {
            InstanceDataCollection idc = GetInstanceDataCollection();

            InstanceData[] ids = new InstanceData[idc.Count];
            idc.CopyTo(ids, 0);

            Assert.Equal("% User Time", idc.CounterName);

            for (int i = 0; i < idc.Count; i++)
            {
                string instanceName = ids[i].InstanceName;
                Assert.Equal(instanceName, idc[instanceName].InstanceName);
                Assert.Equal(ids[i].RawValue, idc[instanceName].RawValue);
                Assert.True(idc.Contains(instanceName));
            }
        }