diff --git a/config/checkstyle-checks.xml b/config/checkstyle-checks.xml
index ea26192f8..9cecd89dd 100644
--- a/config/checkstyle-checks.xml
+++ b/config/checkstyle-checks.xml
@@ -331,7 +331,14 @@
         <module name="EmptyCatchBlock"/>
         <module name="LeftCurly"/>
         <module name="NeedBraces"/>
-        <!-- modified -->
+
+        <!-- Class Design -->
+        <module name="DesignForExtension">
+            <property name="ignoredAnnotations"
+                value="Override, Test, Before, After, BeforeClass, AfterClass"/>
+            <property name="ignoredAnnotations"
+                value="BeforeAll, AfterAll, BeforeEach, AfterEach"/>
+        </module>
         <module name="HideUtilityClassConstructor"/>
         <module name="InnerTypeLast"/>
         <module name="InterfaceIsType"/>
diff --git a/net.sf.eclipsecs.core/src/net/sf/eclipsecs/core/config/configtypes/AbstractConfigurationType.java b/net.sf.eclipsecs.core/src/net/sf/eclipsecs/core/config/configtypes/AbstractConfigurationType.java
index 7007a0a66..03ea6ff4e 100644
--- a/net.sf.eclipsecs.core/src/net/sf/eclipsecs/core/config/configtypes/AbstractConfigurationType.java
+++ b/net.sf.eclipsecs.core/src/net/sf/eclipsecs/core/config/configtypes/AbstractConfigurationType.java
@@ -157,6 +157,19 @@ public CheckstyleConfigurationFile getCheckstyleConfiguration(
     return data;
   }
 
+  /**
+   * Retrieves the bytes of an additional properties bundle associated with the Checkstyle
+   * configuration.
+   * <p>
+   * This method attempts to find a <code>.properties</code> file with the same base name as the
+   * provided configuration URL.
+   * </p>
+   *
+   * @param checkConfigURL
+   *          the URL of the Checkstyle configuration file
+   * @return an optional containing the bytes of the properties bundle, or empty if it cannot be
+   *         loaded
+   */
   protected Optional<byte[]> getAdditionPropertiesBundleBytes(URL checkConfigURL) {
 
     String location = checkConfigURL.toString();
@@ -189,8 +202,10 @@ protected Optional<byte[]> getAdditionPropertiesBundleBytes(URL checkConfigURL)
    * Gets the property resolver for this configuration type used to expand property values within
    * the checkstyle configuration.
    *
-   * @param checkConfiguration
+   * @param config
    *          the actual check configuration
+   * @param configFile
+   *          the checkstyle configuration file
    * @return the property resolver
    * @throws IOException
    *           error creating the property resolver
@@ -223,6 +238,15 @@ protected PropertyResolver getPropertyResolver(ICheckConfiguration config,
     return multiResolver;
   }
 
+  /**
+   * Reads and returns all bytes from the provided <code>URLConnection</code>.
+   *
+   * @param connection
+   *          the connection to read from
+   * @return the byte array containing the data from the connection
+   * @throws IOException
+   *           if an I/O error occurs while reading from the connection
+   */
   protected byte[] getBytesFromURLConnection(URLConnection connection) throws IOException {
     try (InputStream in = connection.getInputStream()) {
       return ByteStreams.toByteArray(in);
diff --git a/net.sf.eclipsecs.core/src/net/sf/eclipsecs/core/transformer/CheckstyleFileWriter.java b/net.sf.eclipsecs.core/src/net/sf/eclipsecs/core/transformer/CheckstyleFileWriter.java
index f47873c91..3e150e970 100644
--- a/net.sf.eclipsecs.core/src/net/sf/eclipsecs/core/transformer/CheckstyleFileWriter.java
+++ b/net.sf.eclipsecs.core/src/net/sf/eclipsecs/core/transformer/CheckstyleFileWriter.java
@@ -33,7 +33,7 @@
  *
  *
  */
-public class CheckstyleFileWriter {
+public final class CheckstyleFileWriter {
 
   /** An object containing all settings for the checkstyle-file. */
   private final CheckstyleSetting mCheckstyleSetting;
diff --git a/net.sf.eclipsecs.sample/src/net/sf/eclipsecs/sample/checks/MethodLimitCheck.java b/net.sf.eclipsecs.sample/src/net/sf/eclipsecs/sample/checks/MethodLimitCheck.java
index f70cdf2a8..96d6add5a 100644
--- a/net.sf.eclipsecs.sample/src/net/sf/eclipsecs/sample/checks/MethodLimitCheck.java
+++ b/net.sf.eclipsecs.sample/src/net/sf/eclipsecs/sample/checks/MethodLimitCheck.java
@@ -24,7 +24,7 @@
 import com.puppycrawl.tools.checkstyle.api.DetailAST;
 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
 
-public class MethodLimitCheck extends AbstractCheck {
+public final class MethodLimitCheck extends AbstractCheck {
 
   private int max = 30;
 
diff --git a/net.sf.eclipsecs.ui/src/net/sf/eclipsecs/ui/ApplicationStartedHandler.java b/net.sf.eclipsecs.ui/src/net/sf/eclipsecs/ui/ApplicationStartedHandler.java
index 9871437d2..0d3e292fe 100644
--- a/net.sf.eclipsecs.ui/src/net/sf/eclipsecs/ui/ApplicationStartedHandler.java
+++ b/net.sf.eclipsecs.ui/src/net/sf/eclipsecs/ui/ApplicationStartedHandler.java
@@ -45,7 +45,7 @@
  * Event handler being called when the eclipse application has started.
  */
 @Component(property = EventConstants.EVENT_TOPIC + "=" + UIEvents.UILifeCycle.APP_STARTUP_COMPLETE)
-public class ApplicationStartedHandler implements EventHandler {
+public final class ApplicationStartedHandler implements EventHandler {
 
   private final CheckFileOnOpenPartListener mPartListener = new CheckFileOnOpenPartListener();
 
diff --git a/net.sf.eclipsecs.ui/src/net/sf/eclipsecs/ui/config/CheckConfigurationWorkingSetEditor.java b/net.sf.eclipsecs.ui/src/net/sf/eclipsecs/ui/config/CheckConfigurationWorkingSetEditor.java
index ebea5b912..ac5e79894 100644
--- a/net.sf.eclipsecs.ui/src/net/sf/eclipsecs/ui/config/CheckConfigurationWorkingSetEditor.java
+++ b/net.sf.eclipsecs.ui/src/net/sf/eclipsecs/ui/config/CheckConfigurationWorkingSetEditor.java
@@ -76,7 +76,7 @@
  * This class provides the editor GUI for a check configuration working set.
  *
  */
-public class CheckConfigurationWorkingSetEditor {
+public final class CheckConfigurationWorkingSetEditor {
 
   //
   // attributes
diff --git a/net.sf.eclipsecs.ui/src/net/sf/eclipsecs/ui/config/widgets/AbstractConfigPropertyWidget.java b/net.sf.eclipsecs.ui/src/net/sf/eclipsecs/ui/config/widgets/AbstractConfigPropertyWidget.java
index 8355190ec..539ae66a3 100644
--- a/net.sf.eclipsecs.ui/src/net/sf/eclipsecs/ui/config/widgets/AbstractConfigPropertyWidget.java
+++ b/net.sf.eclipsecs.ui/src/net/sf/eclipsecs/ui/config/widgets/AbstractConfigPropertyWidget.java
@@ -91,16 +91,15 @@ public void setEnabled(boolean enabled) {
     mValueWidget.setEnabled(enabled);
   }
 
+  /**
+  * Figure out an initial value for the property. This will be,
+  * in order of precedence:
+  * 1) the existing value
+  * 2) a default value overriding the checkstyle default
+  * 3) the checkstyle default value, if specified
+  * 4) blank
+  */
   protected String getInitValue() {
-    //
-    // Figure out an initial value for the property. This will be,
-    // in order of precedence:
-    //
-    // 1) the existing value
-    // 2) a default value overriding the checkstyle default
-    // 3) the checkstyle default value, if specified
-    // 4) blank
-    //
     String initValue = null;
     if (mProp != null) {
       initValue = mProp.getValue();
diff --git a/net.sf.eclipsecs.ui/test/net/sf/eclipsecs/ui/quickfixes/AbstractQuickfixTestCase.java b/net.sf.eclipsecs.ui/test/net/sf/eclipsecs/ui/quickfixes/AbstractQuickfixTestCase.java
index b8cd07a30..233b727a0 100644
--- a/net.sf.eclipsecs.ui/test/net/sf/eclipsecs/ui/quickfixes/AbstractQuickfixTestCase.java
+++ b/net.sf.eclipsecs.ui/test/net/sf/eclipsecs/ui/quickfixes/AbstractQuickfixTestCase.java
@@ -47,7 +47,7 @@
 
 public abstract class AbstractQuickfixTestCase {
 
-  protected void testQuickfix(final String testDataXml, final AbstractASTResolution quickfix)
+  protected final void testQuickfix(final String testDataXml, final AbstractASTResolution quickfix)
           throws Exception {
     try (InputStream stream = getClass().getResourceAsStream(testDataXml)) {
       assertThat(stream).withFailMessage(() -> "Cannot find resource " + testDataXml + " in package "
@@ -56,7 +56,7 @@ protected void testQuickfix(final String testDataXml, final AbstractASTResolutio
     }
   }
 
-  protected void testQuickfix(InputStream testdataStream, AbstractASTResolution quickfix)
+  private void testQuickfix(InputStream testdataStream, AbstractASTResolution quickfix)
           throws Exception {
     QuickfixTestData[] testdata = getTestData(testdataStream);