diff --git a/core/src/test/java/hudson/model/ActionableTest.java b/core/src/test/java/hudson/model/ActionableTest.java
index d0ec1b98daa9ab8fed5d14da84e594801cb976cc..202211ddbebb9301b5cdf56b1ba16e4f2b4ed318 100644
--- a/core/src/test/java/hudson/model/ActionableTest.java
+++ b/core/src/test/java/hudson/model/ActionableTest.java
@@ -33,13 +33,14 @@ import static org.junit.Assert.*;
 import java.util.Collections;
 import java.util.List;
 
+import edu.umd.cs.findbugs.annotations.NonNull;
 import org.junit.Assert;
 import org.junit.Test;
 import org.jvnet.hudson.test.Issue;
 
 public class ActionableTest {
 
-    private Actionable thing = new ActionableImpl();
+    private final Actionable thing = new ActionableImpl();
 
     @SuppressWarnings("deprecation")
     @Test
@@ -67,6 +68,7 @@ public class ActionableTest {
         }
 
         @Override
+        @NonNull
         public List<Action> getActions() {
             return specialActions;
         }
@@ -75,7 +77,7 @@ public class ActionableTest {
     @SuppressWarnings("deprecation")
     @Issue("JENKINS-39555")
     @Test
-    public void testExtensionOverrides() throws Exception {
+    public void testExtensionOverrides() {
         ActionableOverride myOverridden = new ActionableOverride();
         InvisibleAction invis = new InvisibleAction() {
         };
@@ -144,11 +146,11 @@ public class ActionableTest {
         thing.addAction(a2);
         assertEquals(Arrays.asList(a1, a2), thing.getActions());
         assertThat(thing.removeAction(a1), is(true));
-        assertEquals(Arrays.asList(a2), thing.getActions());
+        assertEquals(Collections.singletonList(a2), thing.getActions());
         assertThat(thing.removeAction(a1), is(false));
-        assertEquals(Arrays.asList(a2), thing.getActions());
+        assertEquals(Collections.singletonList(a2), thing.getActions());
         assertThat(thing.removeAction(null), is(false));
-        assertEquals(Arrays.asList(a2), thing.getActions());
+        assertEquals(Collections.singletonList(a2), thing.getActions());
     }
 
     @SuppressWarnings("deprecation")
@@ -160,9 +162,9 @@ public class ActionableTest {
         thing.addAction(a2);
         assertEquals(Arrays.asList(a1, a2), thing.getActions());
         assertThat(thing.removeActions(CauseAction.class), is(true));
-        assertEquals(Arrays.asList(a2), thing.getActions());
+        assertEquals(Collections.singletonList(a2), thing.getActions());
         assertThat(thing.removeActions(CauseAction.class), is(false));
-        assertEquals(Arrays.asList(a2), thing.getActions());
+        assertEquals(Collections.singletonList(a2), thing.getActions());
     }
 
     @SuppressWarnings("deprecation")
diff --git a/core/src/test/java/hudson/model/EnvironmentContributingActionTest.java b/core/src/test/java/hudson/model/EnvironmentContributingActionTest.java
index aee451908a112e023b6e471a83297ace359d1049..28c8abbdbf3ee9f560b5c110240c50bcd4235397 100644
--- a/core/src/test/java/hudson/model/EnvironmentContributingActionTest.java
+++ b/core/src/test/java/hudson/model/EnvironmentContributingActionTest.java
@@ -1,5 +1,6 @@
 package hudson.model;
 
+import edu.umd.cs.findbugs.annotations.NonNull;
 import hudson.EnvVars;
 import org.junit.Test;
 
@@ -15,7 +16,7 @@ public class EnvironmentContributingActionTest {
         private boolean wasCalled = false;
 
         @Override
-        public void buildEnvironment(Run<?, ?> run, EnvVars env) {
+        public void buildEnvironment(@NonNull Run<?, ?> run, @NonNull EnvVars env) {
             wasCalled = true;
         }
 
@@ -49,7 +50,7 @@ public class EnvironmentContributingActionTest {
         }
 
         @Override
-        public void buildEnvironment(Run<?, ?> run, EnvVars env) {
+        public void buildEnvironment(@NonNull Run<?, ?> run, @NonNull EnvVars env) {
             wasCalledRun = true;
         }
 
@@ -65,9 +66,8 @@ public class EnvironmentContributingActionTest {
     private final EnvVars envVars = mock(EnvVars.class);
 
     @Test
-    public void testOverrideRunMethodAndCallNewMethod() throws Exception {
-        Run run = mock(Run.class);
-        Node node = mock(Node.class);
+    public void testOverrideRunMethodAndCallNewMethod() {
+        Run<?,?> run = mock(Run.class);
 
         OverrideRun overrideRun = new OverrideRun();
         overrideRun.buildEnvironment(run, envVars);
@@ -77,12 +77,11 @@ public class EnvironmentContributingActionTest {
 
     /**
      * If only non-deprecated method was overridden it would be executed even if someone would call deprecated method.
-     * @throws Exception if happens.
      */
     @Test
     @SuppressWarnings("deprecation")
-    public void testOverrideRunMethodAndCallDeprecatedMethod() throws Exception {
-        AbstractBuild abstractBuild = mock(AbstractBuild.class);
+    public void testOverrideRunMethodAndCallDeprecatedMethod() {
+        AbstractBuild<?,?> abstractBuild = mock(AbstractBuild.class);
         when(abstractBuild.getBuiltOn()).thenReturn(mock(Node.class));
 
         OverrideRun overrideRun = new OverrideRun();
@@ -93,11 +92,10 @@ public class EnvironmentContributingActionTest {
 
     /**
      * {@link AbstractBuild} should work as before.
-     * @throws Exception if happens.
      */
     @Test
-    public void testOverrideAbstractBuildAndCallNewMethodWithAbstractBuild() throws Exception {
-        AbstractBuild abstractBuild = mock(AbstractBuild.class);
+    public void testOverrideAbstractBuildAndCallNewMethodWithAbstractBuild() {
+        AbstractBuild<?,?> abstractBuild = mock(AbstractBuild.class);
 
         OverrideAbstractBuild action = new OverrideAbstractBuild();
         action.buildEnvironment(abstractBuild, envVars);
@@ -107,11 +105,10 @@ public class EnvironmentContributingActionTest {
 
     /**
      * {@link Run} should not execute method that was overridden for {@link AbstractBuild}.
-     * @throws Exception if happens.
      */
     @Test
-    public void testOverrideAbstractBuildAndCallNewMethodWithRun() throws Exception {
-        Run run = mock(Run.class);
+    public void testOverrideAbstractBuildAndCallNewMethodWithRun() {
+        Run<?,?> run = mock(Run.class);
 
         OverrideAbstractBuild action = new OverrideAbstractBuild();
         action.buildEnvironment(run, envVars);
@@ -121,11 +118,10 @@ public class EnvironmentContributingActionTest {
 
     /**
      * If someone wants to use overridden deprecated method, it would still work.
-     * @throws Exception if happens.
      */
     @Test
-    public void testOverrideAbstractBuildAndCallDeprecatedMethod() throws Exception {
-        AbstractBuild abstractBuild = mock(AbstractBuild.class);
+    public void testOverrideAbstractBuildAndCallDeprecatedMethod() {
+        AbstractBuild<?,?> abstractBuild = mock(AbstractBuild.class);
 
         OverrideAbstractBuild overrideRun = new OverrideAbstractBuild();
         overrideRun.buildEnvVars(abstractBuild, envVars);
@@ -134,8 +130,8 @@ public class EnvironmentContributingActionTest {
     }
 
     @Test
-    public void testOverrideBothAndCallNewMethod() throws Exception {
-        Run run = mock(Run.class);
+    public void testOverrideBothAndCallNewMethod() {
+        Run<?,?> run = mock(Run.class);
 
         OverrideBoth overrideRun = new OverrideBoth();
         overrideRun.buildEnvironment(run, envVars);
@@ -144,8 +140,8 @@ public class EnvironmentContributingActionTest {
     }
 
     @Test
-    public void testOverrideBothAndCallDeprecatedMethod() throws Exception {
-        AbstractBuild abstractBuild = mock(AbstractBuild.class);
+    public void testOverrideBothAndCallDeprecatedMethod() {
+        AbstractBuild<?,?> abstractBuild = mock(AbstractBuild.class);
 
         OverrideBoth overrideRun = new OverrideBoth();
         overrideRun.buildEnvVars(abstractBuild, envVars);