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/ImperativeProgramming.java

@@ -31,23 +31,20 @@ import java.util.List;
 import java.util.Map;
 
 /**
- * Imperative-style programming to iterate over the list and get the names of
- * cars made later than the year 2000. We then sort the models in ascending
- * order by year.
- * 
+ * Imperative-style programming to iterate over the list and get the names of cars made later than
+ * the year 2000. We then sort the models in ascending order by year.
+ *
  * <p>As you can see, there's a lot of looping in this code. First, the
- * getModelsAfter2000UsingFor method takes a list of cars as its parameter. It
- * extracts or filters out cars made after the year 2000, putting them into a
- * new list named carsSortedByYear. Next, it sorts that list in ascending order
- * by year-of-make. Finally, it loops through the list carsSortedByYear to get
- * the model names and returns them in a list.
- * 
+ * getModelsAfter2000UsingFor method takes a list of cars as its parameter. It extracts or filters
+ * out cars made after the year 2000, putting them into a new list named carsSortedByYear. Next, it
+ * sorts that list in ascending order by year-of-make. Finally, it loops through the list
+ * carsSortedByYear to get the model names and returns them in a list.
+ *
  * <p>This short example demonstrates what I call the effect of statements. While
- * functions and methods in general can be used as expressions, the {@link Collections}
- * sort method doesn't return a result. Because it is used as a statement, it
- * mutates the list given as argument. Both of the for loops also mutate lists
- * as they iterate. Being statements, that's just how these elements work. As a
- * result, the code contains unnecessary garbage variables
+ * functions and methods in general can be used as expressions, the {@link Collections} sort method
+ * doesn't return a result. Because it is used as a statement, it mutates the list given as
+ * argument. Both of the for loops also mutate lists as they iterate. Being statements, that's just
+ * how these elements work. As a result, the code contains unnecessary garbage variables
  */
 public class ImperativeProgramming {
   private ImperativeProgramming() {
@@ -55,6 +52,7 @@ public class ImperativeProgramming {
 
   /**
    * Method to return the car models built after year 2000 using for loops.
+   *
    * @param cars {@link List} of {@link Car} to iterate over
    * @return {@link List} of {@link String} of car models built after year 2000
    */
@@ -80,16 +78,16 @@ public class ImperativeProgramming {
 
     return models;
   }
-  
+
   /**
-   * Method to group cars by category using for loops
-   * 
+   * Method to group cars by category using for loops.
+   *
    * @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) {
     Map<Category, List<Car>> groupingByCategory = new HashMap<>();
-    for (Car car: cars) {
+    for (Car car : cars) {
       if (groupingByCategory.containsKey(car.getCategory())) {
         groupingByCategory.get(car.getCategory()).add(car);
       } else {
@@ -100,33 +98,34 @@ public class ImperativeProgramming {
     }
     return groupingByCategory;
   }
-  
+
   /**
-   * Method to get all Sedan cars belonging to a group of persons sorted by year of manufacture using for loops 
-   * 
+   * Method to get all Sedan cars belonging to a group of persons sorted by year of manufacture
+   * using for loops.
+   *
    * @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) {
     List<Car> cars = new ArrayList<>();
-    for (Person person: persons) {
+    for (Person person : persons) {
       cars.addAll(person.getCars());
     }
-  
+
     List<Car> sedanCars = new ArrayList<>();
-    for (Car car: cars) {
+    for (Car car : cars) {
       if (Category.SEDAN.equals(car.getCategory())) {
         sedanCars.add(car);
       }
     }
-  
+
     sedanCars.sort(new Comparator<Car>() {
       @Override
       public int compare(Car o1, Car o2) {
         return o1.getYear() - o2.getYear();
       }
     });
-  
+
     return sedanCars;
   }
 }