diff --git a/src/main/java/org/junit/Assert.java b/src/main/java/org/junit/Assert.java
index d7deb06bb33e..c775035f2d32 100755
--- a/src/main/java/org/junit/Assert.java
+++ b/src/main/java/org/junit/Assert.java
@@ -36,7 +36,7 @@ protected Assert() {
      * okay)
      * @param condition condition to be checked
      */
-    static public void assertTrue(String message, boolean condition) {
+    public static void assertTrue(String message, boolean condition) {
         if (!condition) {
             fail(message);
         }
@@ -48,7 +48,7 @@ static public void assertTrue(String message, boolean condition) {
      *
      * @param condition condition to be checked
      */
-    static public void assertTrue(boolean condition) {
+    public static void assertTrue(boolean condition) {
         assertTrue(null, condition);
     }
 
@@ -60,7 +60,7 @@ static public void assertTrue(boolean condition) {
      * okay)
      * @param condition condition to be checked
      */
-    static public void assertFalse(String message, boolean condition) {
+    public static void assertFalse(String message, boolean condition) {
         assertTrue(message, !condition);
     }
 
@@ -70,7 +70,7 @@ static public void assertFalse(String message, boolean condition) {
      *
      * @param condition condition to be checked
      */
-    static public void assertFalse(boolean condition) {
+    public static void assertFalse(boolean condition) {
         assertFalse(null, condition);
     }
 
@@ -81,7 +81,7 @@ static public void assertFalse(boolean condition) {
      * okay)
      * @see AssertionError
      */
-    static public void fail(String message) {
+    public static void fail(String message) {
         if (message == null) {
             throw new AssertionError();
         }
@@ -91,7 +91,7 @@ static public void fail(String message) {
     /**
      * Fails a test with no message.
      */
-    static public void fail() {
+    public static void fail() {
         fail(null);
     }
 
@@ -106,11 +106,12 @@ static public void fail() {
      * @param expected expected value
      * @param actual actual value
      */
-    static public void assertEquals(String message, Object expected,
+    public static void assertEquals(String message, Object expected,
             Object actual) {
         if (equalsRegardingNull(expected, actual)) {
             return;
-        } else if (expected instanceof String && actual instanceof String) {
+        }
+        if (expected instanceof String && actual instanceof String) {
             String cleanMessage = message == null ? "" : message;
             throw new ComparisonFailure(cleanMessage, (String) expected,
                     (String) actual);
@@ -140,7 +141,7 @@ private static boolean isEquals(Object expected, Object actual) {
      * @param expected expected value
      * @param actual the value to check against <code>expected</code>
      */
-    static public void assertEquals(Object expected, Object actual) {
+    public static void assertEquals(Object expected, Object actual) {
         assertEquals(null, expected, actual);
     }
 
@@ -155,7 +156,7 @@ static public void assertEquals(Object expected, Object actual) {
      * @param unexpected unexpected value to check
      * @param actual the value to check against <code>unexpected</code>
      */
-    static public void assertNotEquals(String message, Object unexpected,
+    public static void assertNotEquals(String message, Object unexpected,
             Object actual) {
         if (equalsRegardingNull(unexpected, actual)) {
             failEquals(message, actual);
@@ -171,7 +172,7 @@ static public void assertNotEquals(String message, Object unexpected,
      * @param unexpected unexpected value to check
      * @param actual the value to check against <code>unexpected</code>
      */
-    static public void assertNotEquals(Object unexpected, Object actual) {
+    public static void assertNotEquals(Object unexpected, Object actual) {
         assertNotEquals(null, unexpected, actual);
     }
 
@@ -194,7 +195,7 @@ private static void failEquals(String message, Object actual) {
      * @param unexpected unexpected value to check
      * @param actual the value to check against <code>unexpected</code>
      */
-    static public void assertNotEquals(String message, long unexpected, long actual) {
+    public static void assertNotEquals(String message, long unexpected, long actual) {
         if (unexpected == actual) {
             failEquals(message, Long.valueOf(actual));
         }
@@ -207,7 +208,7 @@ static public void assertNotEquals(String message, long unexpected, long actual)
      * @param unexpected unexpected value to check
      * @param actual the value to check against <code>unexpected</code>
      */
-    static public void assertNotEquals(long unexpected, long actual) {
+    public static void assertNotEquals(long unexpected, long actual) {
         assertNotEquals(null, unexpected, actual);
     }
 
@@ -226,7 +227,7 @@ static public void assertNotEquals(long unexpected, long actual) {
      * <code>actual</code> for which both numbers are still
      * considered equal.
      */
-    static public void assertNotEquals(String message, double unexpected,
+    public static void assertNotEquals(String message, double unexpected,
             double actual, double delta) {
         if (!doubleIsDifferent(unexpected, actual, delta)) {
             failEquals(message, Double.valueOf(actual));
@@ -245,7 +246,7 @@ static public void assertNotEquals(String message, double unexpected,
      * <code>actual</code> for which both numbers are still
      * considered equal.
      */
-    static public void assertNotEquals(double unexpected, double actual, double delta) {
+    public static void assertNotEquals(double unexpected, double actual, double delta) {
         assertNotEquals(null, unexpected, actual, delta);
     }
 
@@ -261,7 +262,7 @@ static public void assertNotEquals(double unexpected, double actual, double delt
      * <code>actual</code> for which both numbers are still
      * considered equal.
      */
-    static public void assertNotEquals(float unexpected, float actual, float delta) {
+    public static void assertNotEquals(float unexpected, float actual, float delta) {
         assertNotEquals(null, unexpected, actual, delta);
     }
 
@@ -547,7 +548,7 @@ private static void internalArrayEquals(String message, Object expecteds,
      * <code>actual</code> for which both numbers are still
      * considered equal.
      */
-    static public void assertEquals(String message, double expected,
+    public static void assertEquals(String message, double expected,
             double actual, double delta) {
         if (doubleIsDifferent(expected, actual, delta)) {
             failNotEquals(message, Double.valueOf(expected), Double.valueOf(actual));
@@ -569,7 +570,7 @@ static public void assertEquals(String message, double expected,
      * <code>actual</code> for which both numbers are still
      * considered equal.
      */
-    static public void assertEquals(String message, float expected,
+    public static void assertEquals(String message, float expected,
             float actual, float delta) {
         if (floatIsDifferent(expected, actual, delta)) {
             failNotEquals(message, Float.valueOf(expected), Float.valueOf(actual));
@@ -591,14 +592,14 @@ static public void assertEquals(String message, float expected,
      * <code>actual</code> for which both numbers are still
      * considered equal.
      */
-    static public void assertNotEquals(String message, float unexpected,
+    public static void assertNotEquals(String message, float unexpected,
             float actual, float delta) {
         if (!floatIsDifferent(unexpected, actual, delta)) {
-            failEquals(message, Float.valueOf(actual));
+            failEquals(message, actual);
         }
     }
 
-    static private boolean doubleIsDifferent(double d1, double d2, double delta) {
+    private static boolean doubleIsDifferent(double d1, double d2, double delta) {
         if (Double.compare(d1, d2) == 0) {
             return false;
         }
@@ -609,7 +610,7 @@ static private boolean doubleIsDifferent(double d1, double d2, double delta) {
         return true;
     }
 
-    static private boolean floatIsDifferent(float f1, float f2, float delta) {
+    private static boolean floatIsDifferent(float f1, float f2, float delta) {
         if (Float.compare(f1, f2) == 0) {
             return false;
         }
@@ -627,7 +628,7 @@ static private boolean floatIsDifferent(float f1, float f2, float delta) {
      * @param expected expected long value.
      * @param actual actual long value
      */
-    static public void assertEquals(long expected, long actual) {
+    public static void assertEquals(long expected, long actual) {
         assertEquals(null, expected, actual);
     }
 
@@ -640,7 +641,7 @@ static public void assertEquals(long expected, long actual) {
      * @param expected long expected value.
      * @param actual long actual value
      */
-    static public void assertEquals(String message, long expected, long actual) {
+    public static void assertEquals(String message, long expected, long actual) {
         if (expected != actual) {
             failNotEquals(message, Long.valueOf(expected), Long.valueOf(actual));
         }
@@ -652,7 +653,7 @@ static public void assertEquals(String message, long expected, long actual) {
      *             instead
      */
     @Deprecated
-    static public void assertEquals(double expected, double actual) {
+    public static void assertEquals(double expected, double actual) {
         assertEquals(null, expected, actual);
     }
 
@@ -662,7 +663,7 @@ static public void assertEquals(double expected, double actual) {
      *             instead
      */
     @Deprecated
-    static public void assertEquals(String message, double expected,
+    public static void assertEquals(String message, double expected,
             double actual) {
         fail("Use assertEquals(expected, actual, delta) to compare floating-point numbers");
     }
@@ -679,7 +680,7 @@ static public void assertEquals(String message, double expected,
      * <code>actual</code> for which both numbers are still
      * considered equal.
      */
-    static public void assertEquals(double expected, double actual, double delta) {
+    public static void assertEquals(double expected, double actual, double delta) {
         assertEquals(null, expected, actual, delta);
     }
 
@@ -695,8 +696,7 @@ static public void assertEquals(double expected, double actual, double delta) {
      * <code>actual</code> for which both numbers are still
      * considered equal.
      */
-
-    static public void assertEquals(float expected, float actual, float delta) {
+    public static void assertEquals(float expected, float actual, float delta) {
         assertEquals(null, expected, actual, delta);
     }
 
@@ -708,7 +708,7 @@ static public void assertEquals(float expected, float actual, float delta) {
      * okay)
      * @param object Object to check or <code>null</code>
      */
-    static public void assertNotNull(String message, Object object) {
+    public static void assertNotNull(String message, Object object) {
         assertTrue(message, object != null);
     }
 
@@ -718,7 +718,7 @@ static public void assertNotNull(String message, Object object) {
      *
      * @param object Object to check or <code>null</code>
      */
-    static public void assertNotNull(Object object) {
+    public static void assertNotNull(Object object) {
         assertNotNull(null, object);
     }
 
@@ -730,7 +730,7 @@ static public void assertNotNull(Object object) {
      * okay)
      * @param object Object to check or <code>null</code>
      */
-    static public void assertNull(String message, Object object) {
+    public static void assertNull(String message, Object object) {
         if (object == null) {
             return;
         }
@@ -743,11 +743,11 @@ static public void assertNull(String message, Object object) {
      *
      * @param object Object to check or <code>null</code>
      */
-    static public void assertNull(Object object) {
+    public static void assertNull(Object object) {
         assertNull(null, object);
     }
 
-    static private void failNotNull(String message, Object actual) {
+    private static void failNotNull(String message, Object actual) {
         String formatted = "";
         if (message != null) {
             formatted = message + " ";
@@ -764,7 +764,7 @@ static private void failNotNull(String message, Object actual) {
      * @param expected the expected object
      * @param actual the object to compare to <code>expected</code>
      */
-    static public void assertSame(String message, Object expected, Object actual) {
+    public static void assertSame(String message, Object expected, Object actual) {
         if (expected == actual) {
             return;
         }
@@ -778,7 +778,7 @@ static public void assertSame(String message, Object expected, Object actual) {
      * @param expected the expected object
      * @param actual the object to compare to <code>expected</code>
      */
-    static public void assertSame(Object expected, Object actual) {
+    public static void assertSame(Object expected, Object actual) {
         assertSame(null, expected, actual);
     }
 
@@ -792,7 +792,7 @@ static public void assertSame(Object expected, Object actual) {
      * @param unexpected the object you don't expect
      * @param actual the object to compare to <code>unexpected</code>
      */
-    static public void assertNotSame(String message, Object unexpected,
+    public static void assertNotSame(String message, Object unexpected,
             Object actual) {
         if (unexpected == actual) {
             failSame(message);
@@ -807,11 +807,11 @@ static public void assertNotSame(String message, Object unexpected,
      * @param unexpected the object you don't expect
      * @param actual the object to compare to <code>unexpected</code>
      */
-    static public void assertNotSame(Object unexpected, Object actual) {
+    public static void assertNotSame(Object unexpected, Object actual) {
         assertNotSame(null, unexpected, actual);
     }
 
-    static private void failSame(String message) {
+    private static void failSame(String message) {
         String formatted = "";
         if (message != null) {
             formatted = message + " ";
@@ -819,7 +819,7 @@ static private void failSame(String message) {
         fail(formatted + "expected not same");
     }
 
-    static private void failNotSame(String message, Object expected,
+    private static void failNotSame(String message, Object expected,
             Object actual) {
         String formatted = "";
         if (message != null) {
@@ -829,14 +829,14 @@ static private void failNotSame(String message, Object expected,
                 + ">");
     }
 
-    static private void failNotEquals(String message, Object expected,
+    private static void failNotEquals(String message, Object expected,
             Object actual) {
         fail(format(message, expected, actual));
     }
 
     static String format(String message, Object expected, Object actual) {
         String formatted = "";
-        if (message != null && !message.equals("")) {
+        if (message != null && !"".equals(message)) {
             formatted = message + " ";
         }
         String expectedString = String.valueOf(expected);
diff --git a/src/main/java/org/junit/Assume.java b/src/main/java/org/junit/Assume.java
index b7687f7c1ffa..69fac45cad67 100644
--- a/src/main/java/org/junit/Assume.java
+++ b/src/main/java/org/junit/Assume.java
@@ -34,6 +34,15 @@
  * @since 4.4
  */
 public class Assume {
+
+    /**
+     * Do not instantiate.
+     * @deprecated since 4.13.
+     */
+    @Deprecated
+    public Assume() {
+    }
+
     /**
      * If called with an expression evaluating to {@code false}, the test will halt and be ignored.
      */
diff --git a/src/main/java/org/junit/experimental/results/ResultMatchers.java b/src/main/java/org/junit/experimental/results/ResultMatchers.java
index cf58f1bc499a..98778a9f924e 100644
--- a/src/main/java/org/junit/experimental/results/ResultMatchers.java
+++ b/src/main/java/org/junit/experimental/results/ResultMatchers.java
@@ -14,6 +14,15 @@
  * </pre>
  */
 public class ResultMatchers {
+
+    /**
+     * Do not instantiate.
+     * @deprecated will be private soon.
+     */
+    @Deprecated
+    public ResultMatchers() {
+    }
+
     /**
      * Matches if the tests are all successful
      */
diff --git a/src/main/java/org/junit/experimental/theories/internal/Assignments.java b/src/main/java/org/junit/experimental/theories/internal/Assignments.java
index a94c8a5e00b1..6626797ef089 100644
--- a/src/main/java/org/junit/experimental/theories/internal/Assignments.java
+++ b/src/main/java/org/junit/experimental/theories/internal/Assignments.java
@@ -47,7 +47,7 @@ public static Assignments allUnassigned(Method testMethod,
     }
 
     public boolean isComplete() {
-        return unassigned.size() == 0;
+        return unassigned.isEmpty();
     }
 
     public ParameterSignature nextUnassigned() {
@@ -55,11 +55,10 @@ public ParameterSignature nextUnassigned() {
     }
 
     public Assignments assignNext(PotentialAssignment source) {
-        List<PotentialAssignment> assigned = new ArrayList<PotentialAssignment>(
-                this.assigned);
-        assigned.add(source);
+        List<PotentialAssignment> potentialAssignments = new ArrayList<PotentialAssignment>(assigned);
+        potentialAssignments.add(source);
 
-        return new Assignments(assigned, unassigned.subList(1,
+        return new Assignments(potentialAssignments, unassigned.subList(1,
                 unassigned.size()), clazz);
     }
 
@@ -77,7 +76,7 @@ public List<PotentialAssignment> potentialsForNextUnassigned()
         ParameterSignature unassigned = nextUnassigned();
         List<PotentialAssignment> assignments = getSupplier(unassigned).getValueSources(unassigned);
         
-        if (assignments.size() == 0) {
+        if (assignments.isEmpty()) {
             assignments = generateAssignmentsFromTypeAlone(unassigned);
         }
         
diff --git a/src/main/java/org/junit/internal/Classes.java b/src/main/java/org/junit/internal/Classes.java
index 154603d2e4f6..beca4453ae2f 100644
--- a/src/main/java/org/junit/internal/Classes.java
+++ b/src/main/java/org/junit/internal/Classes.java
@@ -6,6 +6,15 @@
  * Miscellaneous functions dealing with classes.
  */
 public class Classes {
+
+    /**
+     * Do not instantiate.
+     * @deprecated will be private soon.
+     */
+    @Deprecated
+    public Classes() {
+    }
+
     /**
      * Returns Class.forName for {@code className} using the current thread's class loader.
      *
diff --git a/src/main/java/org/junit/internal/TextListener.java b/src/main/java/org/junit/internal/TextListener.java
index 9aa56c75f5ec..a75e80d50618 100644
--- a/src/main/java/org/junit/internal/TextListener.java
+++ b/src/main/java/org/junit/internal/TextListener.java
@@ -58,7 +58,7 @@ protected void printHeader(long runTime) {
 
     protected void printFailures(Result result) {
         List<Failure> failures = result.getFailures();
-        if (failures.size() == 0) {
+        if (failures.isEmpty()) {
             return;
         }
         if (failures.size() == 1) {
diff --git a/src/main/java/org/junit/internal/matchers/TypeSafeMatcher.java b/src/main/java/org/junit/internal/matchers/TypeSafeMatcher.java
index 4e2cc1264d09..fb25982bbd4d 100644
--- a/src/main/java/org/junit/internal/matchers/TypeSafeMatcher.java
+++ b/src/main/java/org/junit/internal/matchers/TypeSafeMatcher.java
@@ -40,7 +40,7 @@ private static Class<?> findExpectedType(Class<?> fromClass) {
     }
 
     private static boolean isMatchesSafelyMethod(Method method) {
-        return method.getName().equals("matchesSafely")
+        return "matchesSafely".equals(method.getName())
                 && method.getParameterTypes().length == 1
                 && !method.isSynthetic();
     }
diff --git a/src/main/java/org/junit/runners/BlockJUnit4ClassRunner.java b/src/main/java/org/junit/runners/BlockJUnit4ClassRunner.java
index 8c3cef6c9d91..822f8dc47bfa 100644
--- a/src/main/java/org/junit/runners/BlockJUnit4ClassRunner.java
+++ b/src/main/java/org/junit/runners/BlockJUnit4ClassRunner.java
@@ -5,6 +5,7 @@
 
 import java.util.List;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.TimeUnit;
 
 import org.junit.After;
@@ -56,7 +57,7 @@
  */
 public class BlockJUnit4ClassRunner extends ParentRunner<FrameworkMethod> {
 
-    private final ConcurrentHashMap<FrameworkMethod, Description> methodDescriptions = new ConcurrentHashMap<FrameworkMethod, Description>();
+    private final ConcurrentMap<FrameworkMethod, Description> methodDescriptions = new ConcurrentHashMap<FrameworkMethod, Description>();
 
     /**
      * Creates a BlockJUnit4ClassRunner to run {@code testClass}
@@ -189,6 +190,7 @@ private boolean hasOneConstructor() {
      * Adds to {@code errors} for each method annotated with {@code @Test},
      * {@code @Before}, or {@code @After} that is not a public, void instance
      * method with no arguments.
+     * @deprecated
      */
     @Deprecated
     protected void validateInstanceMethods(List<Throwable> errors) {
@@ -196,7 +198,7 @@ protected void validateInstanceMethods(List<Throwable> errors) {
         validatePublicVoidNoArgMethods(Before.class, false, errors);
         validateTestMethods(errors);
 
-        if (computeTestMethods().size() == 0) {
+        if (computeTestMethods().isEmpty()) {
             errors.add(new Exception("No runnable methods"));
         }
     }
@@ -326,6 +328,7 @@ protected Statement possiblyExpectingExceptions(FrameworkMethod method,
      * Returns a {@link Statement}: if {@code method}'s {@code @Test} annotation
      * has the {@code timeout} attribute, throw an exception if {@code next}
      * takes more than the specified number of milliseconds.
+     * @deprecated
      */
     @Deprecated
     protected Statement withPotentialTimeout(FrameworkMethod method,
@@ -379,12 +382,13 @@ private Statement withRules(FrameworkMethod method, Object target,
 
     private Statement withMethodRules(FrameworkMethod method, List<TestRule> testRules,
             Object target, Statement result) {
+        Statement withMethodRules = result;
         for (org.junit.rules.MethodRule each : getMethodRules(target)) {
-            if (!testRules.contains(each)) {
-                result = each.apply(result, method, target);
+            if (!(each instanceof TestRule && testRules.contains(each))) {
+                withMethodRules = each.apply(withMethodRules, method, target);
             }
         }
-        return result;
+        return withMethodRules;
     }
 
     private List<org.junit.rules.MethodRule> getMethodRules(Object target) {