Resolves checkstyle errors for collection-pipeline, command, commander (#1061)

* Reduces checkstyle errors in collection-pipeline

* Reduces checkstyle errors in command

* Reduces checkstyle errors in commander

collection-pipeline/src/main/java/com/iluwatar/collectionpipeline/FunctionalProgramming.java

@@ -30,20 +30,17 @@ import java.util.stream.Collectors;
 
 /**
  * Iterating and sorting with a collection pipeline
- * 
+ *
  * <p>In functional programming, it's common to sequence complex operations through
- * a series of smaller modular functions or operations. The series is called a
- * composition of functions, or a function composition. When a collection of
- * data flows through a function composition, it becomes a collection pipeline.
- * Function Composition and Collection Pipeline are two design patterns
- * frequently used in functional-style programming.
- * 
+ * a series of smaller modular functions or operations. The series is called a composition of
+ * functions, or a function composition. When a collection of data flows through a function
+ * composition, it becomes a collection pipeline. Function Composition and Collection Pipeline are
+ * two design patterns frequently used in functional-style programming.
+ *
  * <p>Instead of passing a lambda expression to the map method, we passed the
- * method reference Car::getModel. Likewise, instead of passing the lambda
- * expression car -> car.getYear() to the comparing method, we passed the method
- * reference Car::getYear. Method references are short, concise, and expressive.
- * It is best to use them wherever possible.
- * 
+ * method reference Car::getModel. Likewise, instead of passing the lambda expression car ->
+ * car.getYear() to the comparing method, we passed the method reference Car::getYear. Method
+ * references are short, concise, and expressive. It is best to use them wherever possible.
  */
 public class FunctionalProgramming {
   private FunctionalProgramming() {
@@ -51,35 +48,35 @@ public class FunctionalProgramming {
 
   /**
    * Method to get models using for collection pipeline.
-   * 
+   *
    * @param cars {@link List} of {@link Car} to be used for filtering
    * @return {@link List} of {@link String} representing models built after year 2000
    */
   public static List<String> getModelsAfter2000(List<Car> cars) {
     return cars.stream().filter(car -> car.getYear() > 2000)
-      .sorted(Comparator.comparing(Car::getYear))
-      .map(Car::getModel).collect(Collectors.toList());
+        .sorted(Comparator.comparing(Car::getYear))
+        .map(Car::getModel).collect(Collectors.toList());
   }
-  
+
   /**
-   * Method to group cars by category using groupingBy
-   * 
+   * Method to group cars by category using groupingBy.
+   *
    * @param cars {@link List} of {@link Car} to be used for grouping
    * @return {@link Map} with category as key and cars belonging to that category as value
    */
   public static Map<Category, List<Car>> getGroupingOfCarsByCategory(List<Car> cars) {
     return cars.stream().collect(Collectors.groupingBy(Car::getCategory));
   }
-  
+
   /**
-   * Method to get all Sedan cars belonging to a group of persons sorted by year of manufacture 
-   * 
+   * Method to get all Sedan cars belonging to a group of persons sorted by year of manufacture.
+   *
    * @param persons {@link List} of {@link Person} to be used
    * @return {@link List} of {@link Car} to belonging to the group
    */
   public static List<Car> getSedanCarsOwnedSortedByDate(List<Person> persons) {
     return persons.stream().map(Person::getCars).flatMap(List::stream)
-      .filter(car -> Category.SEDAN.equals(car.getCategory()))
-      .sorted(Comparator.comparing(Car::getYear)).collect(Collectors.toList());
+        .filter(car -> Category.SEDAN.equals(car.getCategory()))
+        .sorted(Comparator.comparing(Car::getYear)).collect(Collectors.toList());
   }
 }