LANG-1085: Add a circuit breaker implementation

add since javadoc tags

fix javadoc warning

src/main/java/org/apache/commons/lang3/concurrent/AbstractCircuitBreaker.java

@@ -24,6 +24,7 @@ import java.util.concurrent.atomic.AtomicReference;
  * Base class for circuit breakers.
  *
  * @param <T> the type of the value monitored by this circuit breaker
+ * @since 3.5
  */
 public abstract class AbstractCircuitBreaker<T> implements CircuitBreaker<T> {
     /**
@@ -39,7 +40,7 @@ public abstract class AbstractCircuitBreaker<T> implements CircuitBreaker<T> {
     private final PropertyChangeSupport changeSupport;
 
     /**
-     * Creates an {@AbstractCircuitBreaker}. It also creates an internal {@code PropertyChangeSupport}.
+     * Creates an {@code AbstractCircuitBreaker}. It also creates an internal {@code PropertyChangeSupport}.
      */
     public AbstractCircuitBreaker() {
         changeSupport = new PropertyChangeSupport(this);

src/main/java/org/apache/commons/lang3/concurrent/CircuitBreaker.java

@@ -37,6 +37,7 @@ package org.apache.commons.lang3.concurrent;
  * </p>
  *
  * @param <T> the type of the value monitored by this circuit breaker
+ * @since 3.5
  */
 public interface CircuitBreaker<T> {
     /**

src/main/java/org/apache/commons/lang3/concurrent/CircuitBreakingException.java

@@ -21,6 +21,7 @@ package org.apache.commons.lang3.concurrent;
  * An exception class used for reporting runtime error conditions related to
  * circuit breakers.
  * </p>
+ * @since 3.5
  */
 public class CircuitBreakingException extends RuntimeException {
     /**

src/main/java/org/apache/commons/lang3/concurrent/EventCountCircuitBreaker.java

@@ -133,6 +133,7 @@ import java.util.concurrent.atomic.AtomicReference;
  * guarantee that the circuit breaker is triggered at a specific point in time; there may
  * be some delay (less than a check interval).</li>
  * </ul>
+ * @since 3.5
  */
 public class EventCountCircuitBreaker extends AbstractCircuitBreaker<Integer> {
 

src/main/java/org/apache/commons/lang3/concurrent/ThresholdCircuitBreaker.java

@@ -49,6 +49,7 @@ import java.util.concurrent.atomic.AtomicLong;
  * </pre>
  *
  * <p>#Thread safe#</p>
+ * @since 3.5
  */
 public class ThresholdCircuitBreaker extends AbstractCircuitBreaker<Long> {
     /**