Remove unnecessary casts

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

@@ -245,7 +245,7 @@ public class BagUtils {
      */
     @SuppressWarnings("unchecked") // OK, empty bag is compatible with any type
     public static <E> Bag<E> emptyBag() {
-        return (Bag<E>) EMPTY_BAG;
+        return EMPTY_BAG;
     }
 
     /**

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

@@ -102,6 +102,6 @@ public class QueueUtils {
      */
     @SuppressWarnings("unchecked") // OK, empty queue is compatible with any type
     public static <E> Queue<E> emptyQueue() {
-        return (Queue<E>) EMPTY_QUEUE;
+        return EMPTY_QUEUE;
     }
 }

src/main/java/org/apache/commons/collections4/functors/ConstantFactory.java

@@ -51,7 +51,7 @@ public class ConstantFactory<T> implements Factory<T>, Serializable {
     @SuppressWarnings("unchecked") // The null factory works for all object types
     public static <T> Factory<T> constantFactory(final T constantToReturn) {
         if (constantToReturn == null) {
-            return (Factory<T>) NULL_INSTANCE;
+            return NULL_INSTANCE;
         }
         return new ConstantFactory<>(constantToReturn);
     }

src/main/java/org/apache/commons/collections4/functors/ConstantTransformer.java

@@ -50,7 +50,7 @@ public class ConstantTransformer<I, O> implements Transformer<I, O>, Serializabl
      */
     @SuppressWarnings("unchecked") // The null transformer works for all object types
     public static <I, O> Transformer<I, O> nullTransformer() {
-        return (Transformer<I, O>) NULL_INSTANCE;
+        return NULL_INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/functors/DefaultEquator.java

@@ -48,7 +48,7 @@ public class DefaultEquator<T> implements Equator<T>, Serializable {
      */
     @SuppressWarnings("unchecked") // the static instance works for all types
     public static <T> DefaultEquator<T> defaultEquator() {
-        return (DefaultEquator<T>) DefaultEquator.INSTANCE;
+        return DefaultEquator.INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/functors/ExceptionClosure.java

@@ -44,7 +44,7 @@ public final class ExceptionClosure<E> implements Closure<E>, Serializable {
      */
     @SuppressWarnings("unchecked")  // the static instance works for all types
     public static <E> Closure<E> exceptionClosure() {
-        return (Closure<E>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/functors/ExceptionFactory.java

@@ -44,7 +44,7 @@ public final class ExceptionFactory<T> implements Factory<T>, Serializable {
      */
     @SuppressWarnings("unchecked") // the static instance works for all types
     public static <T> Factory<T> exceptionFactory() {
-        return (Factory<T>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/functors/ExceptionPredicate.java

@@ -44,7 +44,7 @@ public final class ExceptionPredicate<T> implements Predicate<T>, Serializable {
      */
     @SuppressWarnings("unchecked") // the static instance works for all types
     public static <T> Predicate<T> exceptionPredicate() {
-        return (Predicate<T>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/functors/ExceptionTransformer.java

@@ -45,7 +45,7 @@ public final class ExceptionTransformer<I, O> implements Transformer<I, O>, Seri
      */
     @SuppressWarnings("unchecked") // the static instance works for all types
     public static <I, O> Transformer<I, O> exceptionTransformer() {
-        return (Transformer<I, O>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/functors/FalsePredicate.java

@@ -43,7 +43,7 @@ public final class FalsePredicate<T> implements Predicate<T>, Serializable {
      */
     @SuppressWarnings("unchecked") // the static instance works for all types
     public static <T> Predicate<T> falsePredicate() {
-        return (Predicate<T>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/functors/NOPClosure.java

@@ -43,7 +43,7 @@ public final class NOPClosure<E> implements Closure<E>, Serializable {
      */
     @SuppressWarnings("unchecked")
     public static <E> Closure<E> nopClosure() {
-        return (Closure<E>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/functors/NOPTransformer.java

@@ -43,7 +43,7 @@ public class NOPTransformer<T> implements Transformer<T, T>, Serializable {
      */
     @SuppressWarnings("unchecked")
     public static <T> Transformer<T, T> nopTransformer() {
-        return (Transformer<T, T>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/functors/NotNullPredicate.java

@@ -43,7 +43,7 @@ public final class NotNullPredicate<T> implements Predicate<T>, Serializable {
      */
     @SuppressWarnings("unchecked")
     public static <T> Predicate<T> notNullPredicate() {
-        return (Predicate<T>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/functors/NullPredicate.java

@@ -43,7 +43,7 @@ public final class NullPredicate<T> implements Predicate<T>, Serializable {
      */
     @SuppressWarnings("unchecked")
     public static <T> Predicate<T> nullPredicate() {
-        return (Predicate<T>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/functors/TruePredicate.java

@@ -43,7 +43,7 @@ public final class TruePredicate<T> implements Predicate<T>, Serializable {
      */
     @SuppressWarnings("unchecked")
     public static <T> Predicate<T> truePredicate() {
-        return (Predicate<T>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/iterators/EmptyIterator.java

@@ -52,7 +52,7 @@ public class EmptyIterator<E> extends AbstractEmptyIterator<E> implements Resett
      */
     @SuppressWarnings("unchecked")
     public static <E> ResettableIterator<E> resettableEmptyIterator() {
-        return (ResettableIterator<E>) RESETTABLE_INSTANCE;
+        return RESETTABLE_INSTANCE;
     }
 
     /**
@@ -62,7 +62,7 @@ public class EmptyIterator<E> extends AbstractEmptyIterator<E> implements Resett
      */
     @SuppressWarnings("unchecked")
     public static <E> Iterator<E> emptyIterator() {
-        return (Iterator<E>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/iterators/EmptyListIterator.java

@@ -53,7 +53,7 @@ public class EmptyListIterator<E> extends AbstractEmptyIterator<E> implements
      */
     @SuppressWarnings("unchecked")
     public static <E> ResettableListIterator<E> resettableEmptyListIterator() {
-        return (ResettableListIterator<E>) RESETTABLE_INSTANCE;
+        return RESETTABLE_INSTANCE;
     }
 
     /**
@@ -63,7 +63,7 @@ public class EmptyListIterator<E> extends AbstractEmptyIterator<E> implements
      */
     @SuppressWarnings("unchecked")
     public static <E> ListIterator<E> emptyListIterator() {
-        return (ListIterator<E>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/iterators/EmptyMapIterator.java

@@ -42,7 +42,7 @@ public class EmptyMapIterator<K, V> extends AbstractEmptyMapIterator<K, V> imple
      */
     @SuppressWarnings("unchecked")
     public static <K, V> MapIterator<K, V> emptyMapIterator() {
-        return (MapIterator<K, V>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/iterators/EmptyOrderedIterator.java

@@ -41,7 +41,7 @@ public class EmptyOrderedIterator<E> extends AbstractEmptyIterator<E>
      */
     @SuppressWarnings("unchecked")
     public static <E> OrderedIterator<E> emptyOrderedIterator() {
-        return (OrderedIterator<E>) INSTANCE;
+        return INSTANCE;
     }
 
     /**

src/main/java/org/apache/commons/collections4/iterators/EmptyOrderedMapIterator.java

@@ -42,7 +42,7 @@ public class EmptyOrderedMapIterator<K, V> extends AbstractEmptyMapIterator<K, V
      */
     @SuppressWarnings("unchecked")
     public static <K, V> OrderedMapIterator<K, V> emptyOrderedMapIterator() {
-        return (OrderedMapIterator<K, V>) INSTANCE;
+        return INSTANCE;
     }
 
     /**