[java] JSpecify annotations for org.openqa.selenium.grid.jmx (#16431)

[java] JSpecify annotations for `org.openqa.selenium.grid.jmx.JMXHelper`

Co-authored-by: Diego Molina <[email protected]>

Author: mk868

java/src/org/openqa/selenium/grid/jmx/BUILD.bazel

@@ -1,4 +1,4 @@
-load("//java:defs.bzl", "java_library")
+load("//java:defs.bzl", "artifact", "java_library")
 
 java_library(
     name = "jmx",
@@ -8,4 +8,7 @@ java_library(
         "//java/src/org/openqa/selenium/grid/session:__pkg__",
         "//java/test/org/openqa/selenium/grid:__subpackages__",
     ],
+    deps = [
+        artifact("org.jspecify:jspecify"),
+    ],
 )

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

@@ -22,12 +22,15 @@
 import javax.management.InstanceAlreadyExistsException;
 import javax.management.MBeanServer;
 import javax.management.ObjectName;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 
+@NullMarked
 public class JMXHelper {
 
   private static final Logger LOG = Logger.getLogger(JMXHelper.class.getName());
 
-  public MBean register(Object bean) {
+  public @Nullable MBean register(Object bean) {
     MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
     MBean mBean = new MBean(bean);
     try {