Add private constructor for utility classes

Change-Id: I80b73b653e97904605dc62484a7448f3bfbf7210

server/src/main/java/com/vaadin/data/util/BeanUtil.java

@@ -239,5 +239,8 @@ public final class BeanUtil implements Serializable {
                 return false;
             }
         }
+
+        private LazyValidationAvailability() {
+        }
     }
 }

server/src/main/java/com/vaadin/data/validator/BeanValidator.java

@@ -189,5 +189,8 @@ public class BeanValidator implements Validator<Object> {
         private static ValidatorFactory getFactory() {
             return Validation.buildDefaultValidatorFactory();
         }
+
+        private LazyFactoryInitializer() {
+        }
     }
 }

server/src/main/java/com/vaadin/server/ComponentSizeValidator.java

@@ -731,4 +731,7 @@ public class ComponentSizeValidator implements Serializable {
 
     }
 
+    private ComponentSizeValidator() {
+    }
+
 }

server/src/main/java/com/vaadin/server/JsonCodec.java

@@ -993,4 +993,7 @@ public class JsonCodec implements Serializable {
         JSONSerializer serializer = customSerializers.get(value.getClass());
         return serializer.serialize(value, connectorTracker);
     }
+
+    private JsonCodec() {
+    }
 }

server/src/main/java/com/vaadin/server/LegacyPaint.java

@@ -69,4 +69,7 @@ public class LegacyPaint implements Serializable {
 
     }
 
+    private LegacyPaint() {
+    }
+
 }

server/src/main/java/com/vaadin/server/ServletPortletHelper.java

@@ -251,4 +251,7 @@ public class ServletPortletHelper implements Serializable {
 
         return Locale.getDefault();
     }
+
+    private ServletPortletHelper() {
+    }
 }

server/src/main/java/com/vaadin/server/VaadinServiceClassLoaderUtil.java

@@ -54,4 +54,7 @@ class VaadinServiceClassLoaderUtil {
                 new VaadinServiceClassLoaderUtil.GetClassLoaderPrivilegedAction());
     }
 
+    private VaadinServiceClassLoaderUtil() {
+    }
+
 }

server/src/main/java/com/vaadin/ui/declarative/Design.java

@@ -773,4 +773,7 @@ public class Design implements Serializable {
         outputStream.write(doc.html().getBytes(UTF8));
     }
 
+    private Design() {
+    }
+
 }

server/src/main/java/com/vaadin/ui/declarative/DesignAttributeHandler.java

@@ -508,4 +508,7 @@ public class DesignAttributeHandler implements Serializable {
         }
     }
 
+    private DesignAttributeHandler() {
+    }
+
 }

server/src/main/java/com/vaadin/ui/themes/ValoTheme.java

@@ -1072,4 +1072,7 @@ public class ValoTheme {
      * </pre>
      */
     public static final String MENU_APPEAR_ON_HOVER = "valo-menu-hover";
+
+    private ValoTheme() {
+    }
 }

server/src/main/java/com/vaadin/util/ConnectorHelper.java

@@ -98,4 +98,7 @@ public class ConnectorHelper {
         }
     }
 
+    private ConnectorHelper() {
+    }
+
 }

server/src/main/java/com/vaadin/util/FileTypeResolver.java

@@ -392,4 +392,7 @@ public class FileTypeResolver implements Serializable {
     public static Map<String, Resource> getMIMETypeToIconMapping() {
         return Collections.unmodifiableMap(MIMEToIconMap);
     }
+
+    private FileTypeResolver() {
+    }
 }

server/src/main/java/com/vaadin/util/ReflectTools.java

@@ -213,4 +213,7 @@ public class ReflectTools implements Serializable {
         }
         return type;
     }
+
+    private ReflectTools() {
+    }
 }

server/src/main/java/com/vaadin/util/SerializerHelper.java

@@ -154,4 +154,7 @@ public class SerializerHelper {
 
     }
 
+    private SerializerHelper() {
+    }
+
 }

server/src/test/java/com/vaadin/tests/util/TestUtil.java

@@ -43,4 +43,7 @@ public class TestUtil {
                             + " has no match in the first iterable.");
         }
     }
+
+    private TestUtil() {
+    }
 }

server/src/test/java/com/vaadin/ui/ComponentTest.java

@@ -116,4 +116,7 @@ public class ComponentTest {
                 new HashSet<>(Arrays.asList(encodeState.keys())));
     }
 
+    private ComponentTest() {
+    }
+
 }

server/src/test/java/com/vaadin/ui/RichTextAreaTest.java

@@ -22,8 +22,12 @@ import com.vaadin.server.ClientConnector;
 import com.vaadin.server.ServerRpcManager.RpcInvocationException;
 import com.vaadin.shared.ui.richtextarea.RichTextAreaServerRpc;
 import com.vaadin.tests.util.MockUI;
+import static com.vaadin.ui.ComponentTest.getRpcProxy;
+import static com.vaadin.ui.ComponentTest.isDirty;
+import static com.vaadin.ui.ComponentTest.syncToClient;
+import static com.vaadin.ui.ComponentTest.updateDiffState;
 
-public class RichTextAreaTest extends ComponentTest {
+public class RichTextAreaTest  {
 
     @Test
     public void initiallyEmpty() {