Add and fix Checkstyle NoWhitespaceBeforeCaseDefaultColon

src/conf/checkstyle.xml

@@ -61,6 +61,7 @@ limitations under the License.
     <module name="WhitespaceAfter"/>
     <module name="WhitespaceAround"/>
     <module name="NoWhitespaceBefore"/>
+    <module name="NoWhitespaceBeforeCaseDefaultColon"/>
     <module name="ImportOrder">
       <property name="option" value="top"/>
       <property name="groups" value="java,javax,junit,org,com"/>

src/main/java/org/apache/commons/collections4/list/TreeList.java

@@ -277,21 +277,21 @@ public class TreeList<E> extends AbstractList<E> {
          */
         private AVLNode<E> balance() {
             switch (heightRightMinusLeft()) {
-            case 1 :
+            case 1:
-            case 0 :
+            case 0:
-            case -1 :
+            case -1:
                 return this;
-            case -2 :
+            case -2:
                 if (left.heightRightMinusLeft() > 0) {
                     setLeft(left.rotateLeft(), null);
                 }
                 return rotateRight();
-            case 2 :
+            case 2:
                 if (right.heightRightMinusLeft() < 0) {
                     setRight(right.rotateRight(), null);
                 }
                 return rotateLeft();
-            default :
+            default:
                 throw new IllegalStateException("tree inconsistent!");
             }
         }

src/test/java/org/apache/commons/collections4/set/AbstractNavigableSetTest.java

@@ -131,16 +131,17 @@ public abstract class AbstractNavigableSetTest<E> extends AbstractSortedSetTest<
         public E[] getOtherElements() {
             return otherElements;
         }
+
         private NavigableSet<E> getSubSet(final NavigableSet<E> set) {
             final E[] elements = AbstractNavigableSetTest.this.getFullElements();
             switch (type) {
-            case TYPE_SUBSET :
+            case TYPE_SUBSET:
                 return set.subSet(elements[lowBound], inclusive, elements[highBound], inclusive);
-            case TYPE_HEADSET :
+            case TYPE_HEADSET:
                 return set.headSet(elements[highBound], inclusive);
-            case TYPE_TAILSET :
+            case TYPE_TAILSET:
                 return set.tailSet(elements[lowBound], inclusive);
-            default :
+            default:
                 return null;
             }
         }

src/test/java/org/apache/commons/collections4/set/AbstractSortedSetTest.java

@@ -127,13 +127,13 @@ public abstract class AbstractSortedSetTest<E> extends AbstractSetTest<E> {
         private SortedSet<E> getSubSet(final SortedSet<E> set) {
             final E[] elements = AbstractSortedSetTest.this.getFullElements();
             switch (type) {
-            case TYPE_SUBSET :
+            case TYPE_SUBSET:
                 return set.subSet(elements[lowBound], elements[highBound]);
-            case TYPE_HEADSET :
+            case TYPE_HEADSET:
                 return set.headSet(elements[highBound]);
-            case TYPE_TAILSET :
+            case TYPE_TAILSET:
                 return set.tailSet(elements[lowBound]);
-            default :
+            default:
                 return null;
             }
         }