diff --git a/core/src/test/java/hudson/FilePathTest.java b/core/src/test/java/hudson/FilePathTest.java
index 0043abbfa3..d7768a7327 100644
--- a/core/src/test/java/hudson/FilePathTest.java
+++ b/core/src/test/java/hudson/FilePathTest.java
@@ -30,54 +30,33 @@ import hudson.os.WindowsUtil;
 import hudson.remoting.VirtualChannel;
 import hudson.util.NullStream;
 import hudson.util.StreamTaskListener;
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.File;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.io.RandomAccessFile;
-import java.net.ConnectException;
-import java.net.HttpURLConnection;
-import java.net.URL;
-import java.net.URLConnection;
-import java.net.URLStreamHandler;
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.output.NullOutputStream;
+import org.apache.tools.ant.Project;
+import org.apache.tools.ant.taskdefs.Chmod;
+import org.junit.Ignore;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.jvnet.hudson.test.Issue;
+import org.mockito.Mockito;
+
+import java.io.*;
+import java.net.*;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.attribute.FileTime;
 import java.nio.file.attribute.PosixFilePermission;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.EnumSet;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.Future;
-import java.util.concurrent.TimeUnit;
+import java.util.*;
+import java.util.concurrent.*;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
-import org.apache.commons.io.FileUtils;
-import org.apache.commons.io.output.NullOutputStream;
-import org.apache.tools.ant.Project;
-import org.apache.tools.ant.taskdefs.Chmod;
+
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.*;
-import static org.junit.Assert.assertThat;
-import static org.junit.Assume.assumeThat;
-import static org.junit.Assume.assumeTrue;
 import static org.junit.Assume.assumeFalse;
-
-import org.junit.Ignore;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.rules.TemporaryFolder;
-
-import org.jvnet.hudson.test.Issue;
-import org.mockito.Mockito;
+import static org.junit.Assume.assumeTrue;
 import static org.mockito.Mockito.*;
 
 /**
diff --git a/core/src/test/java/hudson/UtilTest.java b/core/src/test/java/hudson/UtilTest.java
index e6c448f430..7c018b50b5 100644
--- a/core/src/test/java/hudson/UtilTest.java
+++ b/core/src/test/java/hudson/UtilTest.java
@@ -24,39 +24,32 @@
  */
 package hudson;
 
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.text.ParseException;
-import java.text.SimpleDateFormat;
-import java.util.Date;
-import java.util.Map;
-import java.util.HashMap;
-import java.util.Locale;
-import java.util.Properties;
-import java.io.ByteArrayOutputStream;
-import java.io.File;
-import java.io.IOException;
-import java.nio.file.attribute.PosixFilePermissions;
-
-import static org.hamcrest.CoreMatchers.is;
-import static org.hamcrest.CoreMatchers.not;
-import static org.hamcrest.CoreMatchers.startsWith;
-import static org.junit.Assert.*;
-
 import hudson.model.TaskListener;
 import hudson.os.WindowsUtil;
+import hudson.util.StreamTaskListener;
 import org.apache.commons.io.FileUtils;
 import org.hamcrest.BaseMatcher;
 import org.hamcrest.Description;
 import org.junit.Assume;
+import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
+import org.junit.rules.TemporaryFolder;
 import org.jvnet.hudson.test.Issue;
 
-import hudson.util.StreamTaskListener;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.PosixFilePermissions;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.*;
 
-import org.junit.Rule;
-import org.junit.rules.TemporaryFolder;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.CoreMatchers.startsWith;
+import static org.junit.Assert.*;
 
 /**
  * @author Kohsuke Kawaguchi
diff --git a/core/src/test/java/jenkins/util/VirtualFileTest.java b/core/src/test/java/jenkins/util/VirtualFileTest.java
index 9ee3c40cc1..e0d6f40583 100644
--- a/core/src/test/java/jenkins/util/VirtualFileTest.java
+++ b/core/src/test/java/jenkins/util/VirtualFileTest.java
@@ -29,6 +29,16 @@ import hudson.FilePath;
 import hudson.Functions;
 import hudson.Util;
 import hudson.model.TaskListener;
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.IOUtils;
+import org.apache.commons.io.input.NullInputStream;
+import org.hamcrest.Description;
+import org.hamcrest.TypeSafeMatcher;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.jvnet.hudson.test.Issue;
+
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
@@ -39,22 +49,11 @@ import java.nio.file.attribute.PosixFilePermissions;
 import java.util.Set;
 import java.util.TreeSet;
 import java.util.stream.Collectors;
-import org.apache.commons.io.FileUtils;
-import org.apache.commons.io.IOUtils;
-import org.apache.commons.io.input.NullInputStream;
-import org.hamcrest.Description;
-import org.hamcrest.TypeSafeMatcher;
-import org.junit.Test;
 
 import static org.hamcrest.Matchers.*;
-import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.junit.Assert.*;
 import static org.junit.Assume.assumeFalse;
 
-import org.junit.Rule;
-import org.junit.rules.TemporaryFolder;
-import org.jvnet.hudson.test.Issue;
-
 public class VirtualFileTest {
 
     @Rule public TemporaryFolder tmp = new TemporaryFolder();
diff --git a/test/src/test/java/hudson/model/DirectoryBrowserSupportTest.java b/test/src/test/java/hudson/model/DirectoryBrowserSupportTest.java
index 3af2089395..8ef6d80574 100644
--- a/test/src/test/java/hudson/model/DirectoryBrowserSupportTest.java
+++ b/test/src/test/java/hudson/model/DirectoryBrowserSupportTest.java
@@ -23,66 +23,40 @@
  */
 package hudson.model;
 
-import hudson.FilePath;
-import hudson.Functions;
-import hudson.Launcher;
+import com.gargoylesoftware.htmlunit.Page;
+import com.gargoylesoftware.htmlunit.UnexpectedPage;
+import com.gargoylesoftware.htmlunit.html.HtmlPage;
+import hudson.*;
 import hudson.tasks.ArtifactArchiver;
 import hudson.tasks.BatchFile;
 import hudson.tasks.Shell;
+import jenkins.model.*;
+import jenkins.util.VirtualFile;
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.IOUtils;
+import org.junit.Assume;
+import org.junit.Rule;
+import org.junit.Test;
+import org.jvnet.hudson.test.*;
+import org.kohsuke.stapler.StaplerRequest;
+import org.kohsuke.stapler.StaplerResponse;
 
-import java.io.File;
-import java.io.IOException;
-import java.io.InputStream;
+import java.io.*;
 import java.net.HttpURLConnection;
+import java.net.URI;
 import java.net.URISyntaxException;
+import java.net.URL;
 import java.nio.file.Files;
+import java.util.*;
 import java.util.stream.Collectors;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
-import org.apache.commons.io.FileUtils;
-import org.junit.Assume;
-import org.junit.Rule;
-import org.junit.Test;
-import org.jvnet.hudson.test.Issue;
-import org.jvnet.hudson.test.Email;
-import org.jvnet.hudson.test.JenkinsRule;
-import org.jvnet.hudson.test.SingleFileSCM;
-import org.jvnet.hudson.test.TestBuilder;
-
-import com.gargoylesoftware.htmlunit.Page;
-import com.gargoylesoftware.htmlunit.UnexpectedPage;
-import com.gargoylesoftware.htmlunit.html.HtmlPage;
-import hudson.ExtensionList;
-import hudson.Util;
-import java.io.ByteArrayInputStream;
-import java.io.FileNotFoundException;
-import java.io.OutputStream;
-import java.net.URI;
-import java.net.URL;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import jenkins.model.ArtifactManager;
-import jenkins.model.ArtifactManagerConfiguration;
-import jenkins.model.ArtifactManagerFactory;
-import jenkins.model.ArtifactManagerFactoryDescriptor;
-import jenkins.model.Jenkins;
-import jenkins.util.VirtualFile;
-import org.apache.commons.io.IOUtils;
-import org.jvnet.hudson.test.TestExtension;
-import org.kohsuke.stapler.StaplerRequest;
-import org.kohsuke.stapler.StaplerResponse;
-
-import static org.hamcrest.CoreMatchers.*;
 import static org.hamcrest.CoreMatchers.allOf;
 import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.CoreMatchers.not;
 import static org.hamcrest.Matchers.*;
-import static org.hamcrest.Matchers.hasSize;
 import static org.junit.Assert.*;
 
 /**