docs: improve consistency of JavaDoc for i18n methods

vaadin-app-layout-flow-parent/vaadin-app-layout-flow/src/main/java/com/vaadin/flow/component/applayout/AppLayout.java

@@ -72,10 +72,9 @@ public class AppLayout extends Component implements RouterLayout, HasStyle {
      * <p>
      * NOTE: Updating the instance that is returned from this method will not
      * update the component if not set again using
-     * {@link AppLayout#setI18n(AppLayoutI18n)}
+     * {@link #setI18n(AppLayoutI18n)}
      *
-     * @return the i18n object. It will be <code>null</code>, if the i18n
-     *         properties are not set.
+     * @return the i18n object or {@code null} if no i18n object has been set
      */
     public AppLayoutI18n getI18n() {
         return i18n;
@@ -85,7 +84,7 @@ public AppLayoutI18n getI18n() {
      * Sets the internationalization properties for this component.
      *
      * @param i18n
-     *            the internationalized properties, not <code>null</code>
+     *            the i18n object, not {@code null}
      */
     public void setI18n(AppLayoutI18n i18n) {
         this.i18n = Objects.requireNonNull(i18n,

vaadin-avatar-flow-parent/vaadin-avatar-flow/src/main/java/com/vaadin/flow/component/avatar/Avatar.java

@@ -134,11 +134,9 @@ public Avatar(String name, String url) {
      * Gets the internationalization object previously set for this component.
      * <p>
      * NOTE: Updating the instance that is returned from this method will not
-     * update the component if not set again using
-     * {@link Avatar#setI18n(AvatarI18n)}
+     * update the component if not set again using {@link #setI18n(AvatarI18n)}
      *
-     * @return the i18n object. It will be <code>null</code>, If the i18n
-     *         properties weren't set.
+     * @return the i18n object or {@code null} if no i18n object has been set
      */
     public AvatarI18n getI18n() {
         return i18n;
@@ -148,7 +146,7 @@ public AvatarI18n getI18n() {
      * Sets the internationalization properties for this component.
      *
      * @param i18n
-     *            the internationalized properties, not <code>null</code>
+     *            the i18n object, not {@code null}
      */
     public void setI18n(AvatarI18n i18n) {
         this.i18n = Objects.requireNonNull(i18n,

vaadin-avatar-flow-parent/vaadin-avatar-flow/src/main/java/com/vaadin/flow/component/avatar/AvatarGroup.java

@@ -646,10 +646,9 @@ public List<AvatarGroupItem> getItems() {
      * <p>
      * NOTE: Updating the instance that is returned from this method will not
      * update the component if not set again using
-     * {@link AvatarGroup#setI18n(AvatarGroupI18n)}
+     * {@link #setI18n(AvatarGroupI18n)}
      *
-     * @return the i18n object. It will be <code>null</code>, If the i18n
-     *         properties weren't set.
+     * @return the i18n object or {@code null} if no i18n object has been set
      */
     public AvatarGroupI18n getI18n() {
         return i18n;
@@ -659,7 +658,7 @@ public AvatarGroupI18n getI18n() {
      * Sets the internationalization properties for this component.
      *
      * @param i18n
-     *            the internationalized properties, not <code>null</code>
+     *            the i18n object, not {@code null}
      */
     public void setI18n(AvatarGroupI18n i18n) {
         this.i18n = Objects.requireNonNull(i18n,

vaadin-combo-box-flow-parent/vaadin-combo-box-flow/src/main/java/com/vaadin/flow/component/combobox/MultiSelectComboBox.java

@@ -537,8 +537,7 @@ public void setKeepFilter(boolean keepFilter) {
      * update the component if not set again using
      * {@link #setI18n(MultiSelectComboBoxI18n)}
      *
-     * @return the i18n object. It will be <code>null</code>, if it has not been
-     *         set previously
+     * @return the i18n object or {@code null} if no i18n object has been set
      */
     public MultiSelectComboBoxI18n getI18n() {
         return i18n;
@@ -548,7 +547,7 @@ public MultiSelectComboBoxI18n getI18n() {
      * Sets the internationalization properties for this component.
      *
      * @param i18n
-     *            the internationalized properties, not <code>null</code>
+     *            the i18n object, not {@code null}
      */
     public void setI18n(MultiSelectComboBoxI18n i18n) {
         this.i18n = Objects.requireNonNull(i18n,

vaadin-date-picker-flow-parent/vaadin-date-picker-flow/src/main/java/com/vaadin/flow/component/datepicker/DatePicker.java

@@ -419,10 +419,9 @@ private void initConnector() {
      * <p>
      * NOTE: Updating the instance that is returned from this method will not
      * update the component if not set again using
-     * {@link DatePicker#setI18n(DatePickerI18n)}
+     * {@link #setI18n(DatePickerI18n)}
      *
-     * @return the i18n object. It will be <code>null</code>, If the i18n
-     *         properties weren't set.
+     * @return the i18n object or {@code null} if no i18n object has been set
      */
     public DatePickerI18n getI18n() {
         return i18n;
@@ -432,7 +431,7 @@ public DatePickerI18n getI18n() {
      * Sets the internationalization properties for this component.
      *
      * @param i18n
-     *            the internationalized properties, not <code>null</code>
+     *            the i18n object, not {@code null}
      */
     public void setI18n(DatePickerI18n i18n) {
         this.i18n = Objects.requireNonNull(i18n,

vaadin-date-time-picker-flow-parent/vaadin-date-time-picker-flow/src/main/java/com/vaadin/flow/component/datetimepicker/DateTimePicker.java

@@ -868,8 +868,7 @@ public LocalDateTime getMax() {
      * update the component if not set again using
      * {@link DateTimePicker#setDatePickerI18n(DatePickerI18n)}
      *
-     * @return the i18n object. It will be <code>null</code>, If the i18n
-     *         properties weren't set.
+     * @return the i18n object or {@code null} if no i18n object has been set
      */
     public DatePickerI18n getDatePickerI18n() {
         return datePickerI18n;
@@ -880,7 +879,7 @@ public DatePickerI18n getDatePickerI18n() {
      * component.
      *
      * @param i18n
-     *            the internationalized properties, not <code>null</code>
+     *            the i18n object, not {@code null}
      */
     public void setDatePickerI18n(DatePickerI18n i18n) {
         this.datePickerI18n = Objects.requireNonNull(i18n,

vaadin-menu-bar-flow-parent/vaadin-menu-bar-flow/src/main/java/com/vaadin/flow/component/menubar/MenuBar.java

@@ -392,11 +392,9 @@ public boolean isReverseCollapseOrder() {
      * Gets the internationalization object previously set for this component.
      * <p>
      * NOTE: Updating the instance that is returned from this method will not
-     * update the component if not set again using
-     * {@link MenuBar#setI18n(MenuBarI18n)}
+     * update the component if not set again using {@link #setI18n(MenuBarI18n)}
      *
-     * @return the i18n object. It will be <code>null</code>, If the i18n
-     *         properties weren't set.
+     * @return the i18n object or {@code null} if no i18n object has been set
      */
     public MenuBarI18n getI18n() {
         return i18n;
@@ -406,7 +404,7 @@ public MenuBarI18n getI18n() {
      * Sets the internationalization properties for this component.
      *
      * @param i18n
-     *            the internationalized properties, not <code>null</code>
+     *            the i18n object, not {@code null}
      */
     public void setI18n(MenuBarI18n i18n) {
         this.i18n = Objects.requireNonNull(i18n,

vaadin-messages-flow-parent/vaadin-messages-flow/src/main/java/com/vaadin/flow/component/messages/MessageInput.java

@@ -129,10 +129,9 @@ public Registration addSubmitListener(
      * <p>
      * NOTE: Updating the instance that is returned from this method will not
      * update the component if not set again using
-     * {@link MessageInput#setI18n(MessageInputI18n)}.
+     * {@link #setI18n(MessageInputI18n)}.
      *
-     * @return the i18n object, or {@code null} if one has not been set with
-     *         {@link #setI18n(MessageInputI18n)}
+     * @return the i18n object or {@code null} if no i18n object has been set
      */
     public MessageInputI18n getI18n() {
         return i18n;

vaadin-rich-text-editor-flow-parent/vaadin-rich-text-editor-flow/src/main/java/com/vaadin/flow/component/richtexteditor/RichTextEditor.java

@@ -73,10 +73,9 @@ public class RichTextEditor
      * <p>
      * NOTE: Updating the instance that is returned from this method will not
      * update the component if not set again using
-     * {@link RichTextEditor#setI18n(RichTextEditorI18n)}
+     * {@link #setI18n(RichTextEditorI18n)}
      *
-     * @return the i18n object. It will be <code>null</code>, If the i18n
-     *         properties weren't set.
+     * @return the i18n object or {@code null} if no i18n object has been set
      */
     public RichTextEditorI18n getI18n() {
         return i18n;
@@ -86,7 +85,7 @@ public RichTextEditorI18n getI18n() {
      * Sets the internationalization properties for this component.
      *
      * @param i18n
-     *            the internationalized properties, not <code>null</code>
+     *            the i18n object, not {@code null}
      */
     public void setI18n(RichTextEditorI18n i18n) {
         this.i18n = Objects.requireNonNull(i18n,

vaadin-side-nav-flow-parent/vaadin-side-nav-flow/src/main/java/com/vaadin/flow/component/sidenav/SideNav.java

@@ -152,11 +152,9 @@ public void setExpanded(boolean expanded) {
      * Gets the internationalization object previously set for this component.
      * <p>
      * NOTE: Updating the instance that is returned from this method will not
-     * update the component if not set again using
-     * {@link SideNav#setI18n(SideNavI18n)}
+     * update the component if not set again using {@link #setI18n(SideNavI18n)}
      *
-     * @return the i18n object. It will be <code>null</code>, If the i18n
-     *         properties weren't set.
+     * @return the i18n object or {@code null} if no i18n object has been set
      */
     public SideNavI18n getI18n() {
         return i18n;
@@ -168,7 +166,7 @@ public SideNavI18n getI18n() {
      * web component.
      *
      * @param i18n
-     *            the internationalized properties, not <code>null</code>
+     *            the i18n object, not {@code null}
      */
     public void setI18n(SideNavI18n i18n) {
         Objects.requireNonNull(i18n,

vaadin-upload-flow-parent/vaadin-upload-flow/src/main/java/com/vaadin/flow/component/upload/Upload.java

@@ -645,7 +645,7 @@ public void setReceiver(Receiver receiver) {
      * Set the internationalization properties for this component.
      *
      * @param i18n
-     *            the internationalized properties, not <code>null</code>
+     *            the i18n object, not {@code null}
      */
     public void setI18n(UploadI18N i18n) {
         this.i18n = Objects.requireNonNull(i18n,
@@ -714,11 +714,9 @@ void runBeforeClientResponse(SerializableConsumer<UI> command) {
      * Get the internationalization object previously set for this component.
      * <p>
      * NOTE: Updating the instance that is returned from this method will not
-     * update the component if not set again using
-     * {@link Upload#setI18n(UploadI18N)}
+     * update the component if not set again using {@link #setI18n(UploadI18N)}
      *
-     * @return the object with the i18n properties. If the i18n properties
-     *         weren't set, the object will return <code>null</code>.
+     * @return the i18n object or {@code null} if no i18n object has been set
      */
     public UploadI18N getI18n() {
         return i18n;