Safe guard time collector.

Author: khatchad

edu.cuny.hunter.streamrefactoring.core/src/edu/cuny/hunter/streamrefactoring/core/utils/TimeCollector.java

@@ -11,12 +11,19 @@ public class TimeCollector {
 
 	private long collectedTime;
 	private long start;
+	private boolean started;
 
 	public void start() {
+		assert !started : "Time colletor is already started.";
+		started = true;
+
 		start = System.currentTimeMillis();
 	}
 
 	public void stop() {
+		assert started : "Trying to stop a time collector that isn't started.";
+		started = false;
+
 		final long elapsed = System.currentTimeMillis() - start;
 		collectedTime += elapsed;
 	}
@@ -26,6 +33,8 @@ public long getCollectedTime() {
 	}
 
 	public void clear() {
+		assert !started : "Shouldn't clear a running time collector.";
+		
 		collectedTime = 0;
 	}
 }