Fixes checkstyle warnings

todolist/core/src/main/java/todolist/json/TodoPersistence.java

@@ -12,7 +12,6 @@ import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.EnumSet;
 import java.util.Set;
-
 import todolist.core.TodoModel;
 import todolist.json.internal.TodoModule;
 
@@ -22,6 +21,9 @@ import todolist.json.internal.TodoModule;
  */
 public class TodoPersistence {
 
+  /**
+   * Used to indicate what parts of a TodoModel to serialize.
+   */
   public enum TodoModelParts {
     SETTINGS, LISTS, LIST_CONTENTS
   }

todolist/core/src/main/java/todolist/json/internal/TodoModelSerializer.java

@@ -4,9 +4,7 @@ import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.databind.JsonSerializer;
 import com.fasterxml.jackson.databind.SerializerProvider;
 import java.io.IOException;
-import java.util.EnumSet;
 import java.util.Set;
-
 import todolist.core.AbstractTodoList;
 import todolist.core.TodoModel;
 import todolist.json.TodoPersistence.TodoModelParts;

todolist/core/src/main/java/todolist/json/internal/TodoModule.java

 package todolist.json.internal;
 
-import java.util.EnumSet;
-import java.util.Set;
-
 import com.fasterxml.jackson.core.Version;
 import com.fasterxml.jackson.databind.module.SimpleModule;
+import java.util.EnumSet;
+import java.util.Set;
 import todolist.core.AbstractTodoList;
 import todolist.core.TodoItem;
 import todolist.core.TodoModel;

todolist/core/src/main/java/todolist/json/internal/TodoSettingsDeserializer.java

@@ -23,12 +23,12 @@ class TodoSettingsDeserializer extends JsonDeserializer<TodoSettings> {
 
   TodoSettings deserialize(JsonNode jsonNode) {
     if (jsonNode instanceof ObjectNode) {
-      ObjectNode objectNode = (ObjectNode) jsonNode;
-      TodoSettings settings = new TodoSettings();
-      JsonNode todoItemsSortOrderNode = objectNode.get(TodoSettings.TODO_ITEM_SORT_ORDER_SETTING);
+      var objectNode = (ObjectNode) jsonNode;
+      var settings = new TodoSettings();
+      var todoItemsSortOrderNode = objectNode.get(TodoSettings.TODO_ITEM_SORT_ORDER_SETTING);
       if (todoItemsSortOrderNode instanceof TextNode) {
         try {
-          TodoItemsSortOrder sortOrder = TodoItemsSortOrder.valueOf(todoItemsSortOrderNode.asText());
+          var sortOrder = TodoItemsSortOrder.valueOf(todoItemsSortOrderNode.asText());
           settings.setTodoItemsSortOrder(sortOrder);
         } catch (IllegalArgumentException iae) {
           // ignore unknown sort order constant

todolist/core/src/main/java/todolist/json/internal/TodoSettingsSerializer.java

@@ -17,7 +17,8 @@ class TodoSettingsSerializer extends JsonSerializer<TodoSettings> {
       SerializerProvider serializerProvider)
       throws IOException {
     jsonGen.writeStartObject();
-    jsonGen.writeStringField(TodoSettings.TODO_ITEM_SORT_ORDER_SETTING, settings.getTodoItemsSortOrder().name());
+    var sortOrderName = settings.getTodoItemsSortOrder().name();
+    jsonGen.writeStringField(TodoSettings.TODO_ITEM_SORT_ORDER_SETTING, sortOrderName);
     jsonGen.writeEndObject();
   }
 }