Adding annotations to validate the check

Author: diemol

java/src/org/openqa/selenium/grid/jmx/JMXHelper.java

@@ -22,11 +22,13 @@
 import javax.management.InstanceAlreadyExistsException;
 import javax.management.MBeanServer;
 import javax.management.ObjectName;
+import org.jspecify.annotations.Nullable;
 
 public class JMXHelper {
 
   private static final Logger LOG = Logger.getLogger(JMXHelper.class.getName());
 
+  @Nullable
   public MBean register(Object bean) {
     MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
     MBean mBean = new MBean(bean);

java/src/org/openqa/selenium/grid/jmx/MBean.java

@@ -34,6 +34,7 @@
 import javax.management.MBeanOperationInfo;
 import javax.management.MalformedObjectNameException;
 import javax.management.ObjectName;
+import org.jspecify.annotations.Nullable;
 
 public class MBean implements DynamicMBean {
 
@@ -57,6 +58,7 @@ private static class AttributeInfo {
       this.setter = setter;
     }
 
+    @Nullable
     MBeanAttributeInfo getMBeanAttributeInfo() {
       try {
         return new MBeanAttributeInfo(name, description, getter, setter);