[WFCORE-5669] Check emptiness with Collection.isEmpty() (remoting)

[boris-unckel]

Fixes https://issues.redhat.com/browse/WFCORE-5669
as part of https://issues.redhat.com/browse/WFCORE-5661

[wildfly-ci]

Core - Full Integration Build 10994 outcome was FAILURE using a merge of a45880a
Summary: Tests failed: 1 (1 new), passed: 4073, ignored: 43 Build time: 02:18:46

Failed tests

org.jboss.as.test.integration.batch.suspend.SuspendBatchletTestCase.testSuspendResume: 	at org.jboss.as.test.integration.batch.suspend.SuspendBatchletTestCase.checkJobExecution(SuspendBatchletTestCase.java:92)
	at org.jboss.as.test.integration.batch.suspend.SuspendBatchletTestCase.testSuspendResume(SuspendBatchletTestCase.java:137)
	at org.jboss.as.arquillian.service.ArquillianService$ExtendedJMXTestRunner.doRunTestMethod(ArquillianService.java:200)
	at org.jboss.as.arquillian.service.ArquillianService$ExtendedJMXTestRunner.runTestMethod(ArquillianService.java:176)
	at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:112)
	at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:46)
	at com.sun.jmx.mbeanserver.MBeanIntrospector.invokeM(MBeanIntrospector.java:237)
	at com.sun.jmx.mbeanserver.PerInterface.invoke(PerInterface.java:138)
	at com.sun.jmx.mbeanserver.MBeanSupport.invoke(MBeanSupport.java:252)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
	at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
	at org.jboss.as.jmx.PluggableMBeanServerImpl$TcclMBeanServer.invoke(PluggableMBeanServerImpl.java:1493)
	at org.jboss.as.jmx.PluggableMBeanServerImpl.invoke(PluggableMBeanServerImpl.java:726)
	at org.jboss.as.jmx.BlockingNotificationMBeanServer.invoke(BlockingNotificationMBeanServer.java:168)
	at org.jboss.as.jmx.AuthorizingMBeanServer.invoke(AuthorizingMBeanServer.java:258)
	at org.jboss.remotingjmx.protocol.v2.ServerProxy$InvokeHandler.handle(ServerProxy.java:950)
	at org.jboss.remotingjmx.protocol.v2.ServerCommon$MessageReciever$1$1.run(ServerCommon.java:153)
	at org.jboss.as.jmx.ServerInterceptorFactory$Interceptor$1.run(ServerInterceptorFactory.java:71)
	at org.jboss.as.jmx.ServerInterceptorFactory$Interceptor$1.run(ServerInterceptorFactory.java:66)
	at org.wildfly.security.auth.server.SecurityIdentity.runAs(SecurityIdentity.java:328)
	at org.wildfly.security.auth.server.SecurityIdentity.runAs(SecurityIdentity.java:285)
	at org.jboss.as.controller.AccessAuditContext.doAs(AccessAuditContext.java:254)
	at org.jboss.as.controller.AccessAuditContext.doAs(AccessAuditContext.java:225)
	at org.jboss.as.jmx.ServerInterceptorFactory$Interceptor.handleEvent(ServerInterceptorFactory.java:66)
	at org.jboss.remotingjmx.protocol.v2.ServerCommon$MessageReciever$1.run(ServerCommon.java:149)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
------- Stdout: -------
 [0m11:47:36,047 INFO  [org.jboss.as.repository] (management-handler-thread - 1) WFLYDR0001: Content added at location /store/work/tc-work/37b47ae8b9c60325/full/testsuite/integration/basic/target/wildfly-batch/standalone/data/content/6a/047998ce27499dbbf2a0c412fb31952f16f82e/content
 [0m [0m11:47:36,049 INFO  [org.jboss.as.server.deployment] (MSC service thread 1-1) WFLYSRV0027: Starting deployment of "suspend-batchlet.war" (runtime-name: "suspend-batchlet.war")
 [0m [33m11:47:36,132 WARN  [org.jboss.as.dependency.private] (MSC service thread 1-6) WFLYSRV0018: Deployment "deployment.suspend-batchlet.war" is using a private module ("org.wildfly.security.manager") which may be changed or removed in future versions without notice.
 [0m [33m11:47:36,132 WARN  [org.jboss.as.dependency.private] (MSC service thread 1-6) WFLYSRV0018: Deployment "deployment.suspend-batchlet.war" is using a private module ("org.jboss.as.controller") which may be changed or removed in future versions without notice.
 [0m [0m11:47:36,137 INFO  [org.jboss.weld.deployer] (MSC service thread 1-5) WFLYWELD0003: Processing weld deployment suspend-batchlet.war
 [0m [0m11:47:36,187 INFO  [io.jaegertracing.internal.JaegerTracer] (MSC service thread 1-5) No shutdown hook registered: Please call close() manually on application shutdown.
 [0m [0m11:47:36,187 INFO  [org.wildfly.microprofile.opentracing.smallrye] (MSC service thread 1-5) WFLYTRAC0001: Tracer initialized: JaegerTracer(version=Java-1.6.0, serviceName=suspend-batchlet.war, reporter=RemoteReporter(sender=org.wildfly.extension.microprofile.opentracing.spi.sender.WildFlySender@1ab81e04, closeEnqueueTimeout=1000), sampler=RemoteControlledSampler(maxOperations=2000, manager=HttpSamplingManager(hostPort=localhost:5778), sampler=ProbabilisticSampler(tags={sampler.type=probabilistic, sampler.param=0.001})), tags={hostname=build22-el7, jaeger.version=Java-1.6.0, ip=127.0.1.1}, zipkinSharedRpcSpan=false, expandExceptionLogs=false, useTraceId128Bit=false)
 [0m [0m11:47:36,220 INFO  [org.jboss.as.arquillian] (MSC service thread 1-5) Arquillian deployment detected: ArquillianConfig[service=jboss.arquillian.config."suspend-batchlet.war",unit=suspend-batchlet.war,tests=[org.jboss.as.test.integration.batch.suspend.SuspendBatchletTestCase]]
 [0m [0m11:47:36,261 INFO  [io.smallrye.metrics] (MSC service thread 1-8) SRMET01001: MicroProfile: Metrics activated (SmallRye Metrics version: 3.0.3)
 [0m [0m11:47:36,448 INFO  [org.wildfly.extension.undertow] (ServerService Thread Pool -- 30) WFLYUT0021: Registered web context: '/suspend-batchlet' for server 'default-server'
 [0m [0m11:47:36,461 INFO  [org.jboss.as.server] (management-handler-thread - 1) WFLYSRV0010: Deployed "suspend-batchlet.war" (runtime-name : "suspend-batchlet.war")
 [0m [0m11:47:36,567 INFO  [org.jboss.as.server] (management-handler-thread - 1) WFLYSRV0272: Suspending server
 [0m [33m11:47:36,569 WARN  [org.wildfly.extension.batch] (management-handler-thread - 1) WFLYBATCH000014: Stopping execution 9 of suspend-batchlet for deployment suspend-batchlet.war
 [0m [0m11:47:36,569 INFO  [org.jberet] (management-handler-thread - 1) JBERET000033: Stopping job execution: 9
	at org.jboss.as.test.integration.batch.suspend.SuspendBatchletTestCase.checkJobExecution(SuspendBatchletTestCase.java:92)
	at org.jboss.as.test.integration.batch.suspend.SuspendBatchletTestCase.testSuspendResume(SuspendBatchletTestCase.java:137)
	at org.jboss.as.arquillian.service.ArquillianService$ExtendedJMXTestRunner.doRunTestMethod(ArquillianService.java:200)
	at org.jboss.as.arquillian.service.ArquillianService$ExtendedJMXTestRunner.runTestMethod(ArquillianService.java:176)
	at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:112)
	at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:46)
	at com.sun.jmx.mbeanserver.MBeanIntrospector.invokeM(MBeanIntrospector.java:237)
	at com.sun.jmx.mbeanserver.PerInterface.invoke(PerInterface.java:138)