[COLLECTIONS-815] Update ClosureUtils Javadoc to match runtime

src/changes/changes.xml

@@ -41,6 +41,7 @@
     <action type="fix" dev="ggregory" due-to="Gary Gregory">Fix generics in IteratorChain.IteratorChain(Collection).</action>
     <action type="fix" dev="ggregory" due-to="Gary Gregory">Fix generics in org.apache.commons.collections4.IteratorUtils.chainedIterator(Collection).</action>
     <action type="fix" dev="ggregory" due-to="Benjamin Confino, Gary Gregory" issue="COLLECTIONS-856">Javadoc: Document interaction between peek and filter iterator #515.</action>
+    <action type="fix" dev="ggregory" due-to="Elia Bertolina, Gary Gregory" issue="COLLECTIONS-815">Javadoc: Update ClosureUtils Javadoc to match runtime.</action>
     <!-- ADD -->
     <action type="add" dev="ggregory" due-to="Gary Gregory">LayerManager.Builder implements Supplier.</action>
     <action type="add" dev="ggregory" due-to="Gary Gregory, hemanth0525">Add CollectionUtils.duplicateList(Collection).</action>

src/main/java/org/apache/commons/collections4/ClosureUtils.java

@@ -103,7 +103,6 @@ public static <E> Closure<E> chainedClosure(final Closure<? super E>... closures
      * @return the {@code chained} closure
      * @throws NullPointerException if the closures collection is null
      * @throws NullPointerException if any closure in the collection is null
-     * @throws IllegalArgumentException if the closures collection is empty
      */
     public static <E> Closure<E> chainedClosure(final Collection<? extends Closure<? super E>> closures) {
         return ChainedClosure.chainedClosure(closures);
@@ -130,10 +129,9 @@ public static <E> Closure<E> doWhileClosure(final Closure<? super E> closure,
      * Gets a Closure that always throws an exception.
      * This could be useful during testing as a placeholder.
      *
-     * @see org.apache.commons.collections4.functors.ExceptionClosure
-     *
      * @param <E>  the type that the closure acts on
      * @return the closure
+     * @see ExceptionClosure
      */
     public static <E> Closure<E> exceptionClosure() {
         return ExceptionClosure.<E>exceptionClosure();
@@ -262,7 +260,6 @@ public static <E> Closure<E> nopClosure() {
      * @return the {@code switch} closure
      * @throws NullPointerException if the map is null
      * @throws NullPointerException if any closure in the map is null
-     * @throws IllegalArgumentException if the map is empty
      * @throws ClassCastException  if the map elements are of the wrong type
      */
     public static <E> Closure<E> switchClosure(final Map<Predicate<E>, Closure<E>> predicatesAndClosures) {
@@ -337,7 +334,6 @@ public static <E> Closure<E> switchClosure(final Predicate<? super E>[] predicat
      * @return the closure
      * @throws NullPointerException if the map is null
      * @throws NullPointerException if any closure in the map is null
-     * @throws IllegalArgumentException if the map is empty
      */
     @SuppressWarnings("unchecked")
     public static <E> Closure<E> switchMapClosure(final Map<? extends E, Closure<E>> objectsAndClosures) {