Make whitespace use around generic tokens consistent and add a checkstyle rule to enforce it.

checkstyle.xml

@@ -55,6 +55,7 @@ limitations under the License.
     <module name="LeftCurly"/>
     <module name="NeedBraces"/>
     <module name="RightCurly"/>
+    <module name="GenericWhitespace"/>
     <module name="WhitespaceAfter"/>
     <module name="NoWhitespaceBefore"/>
  </module>

src/main/java/org/apache/commons/lang3/ClassUtils.java

@@ -1418,7 +1418,7 @@ public class ClassUtils {
                 final Iterator<Class<?>> wrapped = classes.iterator();
 
                 return new Iterator<Class<?>>() {
-                    Iterator<Class<?>> interfaces = Collections.<Class<?>> emptySet().iterator();
+                    Iterator<Class<?>> interfaces = Collections.<Class<?>>emptySet().iterator();
 
                     @Override
                     public boolean hasNext() {

src/main/java/org/apache/commons/lang3/exception/ExceptionUtils.java

@@ -744,7 +744,7 @@ public class ExceptionUtils {
      */
     public static <R> R rethrow(final Throwable throwable) {
         // claim that the typeErasure invocation throws a RuntimeException
-        return ExceptionUtils.<R, RuntimeException> typeErasure(throwable);
+        return ExceptionUtils.<R, RuntimeException>typeErasure(throwable);
     }
 
     /**

src/test/java/org/apache/commons/lang3/reflect/TypeUtilsTest.java

@@ -535,7 +535,7 @@ public class TypeUtilsTest<B> {
     public void testTypesSatisfyVariables() throws SecurityException,
             NoSuchMethodException {
         final Map<TypeVariable<?>, Type> typeVarAssigns = new HashMap<>();
-        final Integer max = TypeUtilsTest.<Integer> stub();
+        final Integer max = TypeUtilsTest.<Integer>stub();
         typeVarAssigns.put(getClass().getMethod("stub").getTypeParameters()[0], Integer.class);
         assertTrue(TypeUtils.typesSatisfyVariables(typeVarAssigns));
         typeVarAssigns.clear();