wip: remove spotbugs error

Author: smola

Diff for: dd-smoke-tests/src/main/groovy/datadog/smoketest/ProcessManager.groovy

@@ -2,6 +2,7 @@ package datadog.smoketest
 
 import datadog.trace.agent.test.utils.PortUtils
 import de.thetaphi.forbiddenapis.SuppressForbidden
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings
 import groovy.transform.CompileStatic
 import spock.lang.AutoCleanup
 import spock.lang.Shared
@@ -90,6 +91,7 @@ abstract class ProcessManager extends Specification {
     final ThreadGroup tg = new ThreadGroup("smoke-output")
     final List<String> testLogMessages = new ArrayList<>()
 
+    @SuppressFBWarnings(value = "UC_USELESS_OBJECT", justification = "Apparent false positive on threads being unused")
     void close() {
       tg.interrupt()
       Thread[] threads = new Thread[tg.activeCount()]