This test makes sure that when
 * {@link HdfsClientConfigKeys#DFS_CLIENT_TEST_DROP_NAMENODE_RESPONSE_NUM_KEY} is set,
 * DFSClient instances can still be created within NN/DN (e.g., the fs instance
 * used by the trash emptier thread in NN)
This test makes sure that when
 * {@link HdfsClientConfigKeys#DFS_CLIENT_TEST_DROP_NAMENODE_RESPONSE_NUM_KEY} is set,
 * DFSClient instances can still be created within NN/DN (e.g., the fs instance
 * used by the trash emptier thread in NN) | TestLossyRetryInvocationHandler.java