The test records the replication counter in RpcManagerImpl at the start of the test and after a put operation, and asserts that it only changed by 1. Occasionally, the assertion fails:

java.lang.AssertionError: expected [1] but found [2]
	at org.testng.Assert.fail(Assert.java:89)
	at org.testng.Assert.failNotEquals(Assert.java:489)
	at org.testng.Assert.assertEquals(Assert.java:118)
	at org.testng.Assert.assertEquals(Assert.java:160)
	at org.infinispan.jmx.RpcManagerMBeanTest.testEnableJmxStats(RpcManagerMBeanTest.java:126)

This happens because replication counter is only incremented after a successful RPC. The test starts when the cluster is considered "formed", that is when all the nodes are included in the read CH on every node. But that doesn't mean that the RPCs pushing state have finished - a pushing node may still be waiting for a response and so it might increment its replication counter after the start of the test.