Improve AbstractTimeBasedTest in sentinel-core

Signed-off-by: Eric Zhao <sczyh16@gmail.com>

sentinel-core/src/test/java/com/alibaba/csp/sentinel/test/AbstractTimeBasedTest.java

@@ -23,28 +23,36 @@ import org.powermock.modules.junit4.PowerMockRunner;
 import com.alibaba.csp.sentinel.util.TimeUtil;
 
 /**
- * Mock support for {@link TimeUtil}
+ * Mock support for {@link TimeUtil}.
  * 
  * @author jason
- *
  */
 @RunWith(PowerMockRunner.class)
 @PrepareForTest({ TimeUtil.class })
 public abstract class AbstractTimeBasedTest {
+
     private long currentMillis = 0;
-    
+
     {
         PowerMockito.mockStatic(TimeUtil.class);
         PowerMockito.when(TimeUtil.currentTimeMillis()).thenReturn(currentMillis);
     }
-    
+
+    protected final void useActualTime() {
+        PowerMockito.when(TimeUtil.currentTimeMillis()).thenCallRealMethod();
+    }
+
     protected final void setCurrentMillis(long cur) {
         currentMillis = cur;
         PowerMockito.when(TimeUtil.currentTimeMillis()).thenReturn(currentMillis);
     }
-    
+
     protected final void sleep(int t) {
         currentMillis += t;
         PowerMockito.when(TimeUtil.currentTimeMillis()).thenReturn(currentMillis);
     }
+
+    protected final void sleepSecond(int timeSec) {
+        sleep(timeSec * 1000);
+    }
 }