intsum=org.apache.dubbo.rpc.cluster.merger.IntSumMerger
longsum=org.apache.dubbo.rpc.cluster.merger.LongSumMerger
floatsum=org.apache.dubbo.rpc.cluster.merger.FloatSumMerger
doublesum=org.apache.dubbo.rpc.cluster.merger.DoubleSumMerger
intfirst=org.apache.dubbo.rpc.cluster.merger.IntFindFirstMerger
intany=org.apache.dubbo.rpc.cluster.merger.IntFindAnyMerger
