Fix review comment

Signed-off-by: Viet Nguyen Duc <[email protected]>

Author: VietND96

java/src/org/openqa/selenium/grid/distributor/local/LocalGridModel.java

@@ -243,7 +243,8 @@ public void purgeDeadNodes() {
         Instant now = Instant.now();
         Instant lastTouched = nodePurgeTimes.getOrDefault(id, Instant.now());
         Instant lostTime =
-            lastTouched.plus(node.getHeartbeatPeriod().multipliedBy(PURGE_TIMEOUT_MULTIPLIER / 2));
+            lastTouched.plus(
+                node.getHeartbeatPeriod().multipliedBy(PURGE_TIMEOUT_MULTIPLIER).dividedBy(2));
         Instant deadTime =
             lastTouched.plus(node.getHeartbeatPeriod().multipliedBy(PURGE_TIMEOUT_MULTIPLIER));
 

java/src/org/openqa/selenium/grid/distributor/local/LocalNodeRegistry.java

@@ -290,6 +290,9 @@ public boolean drain(NodeId nodeId) {
 
   @Override
   public void updateNodeAvailability(URI nodeUri, NodeId id, Availability availability) {
+    Require.nonNull("Node URI", nodeUri);
+    Require.nonNull("Node ID", id);
+    Require.nonNull("Availability", availability);
     Lock writeLock = lock.writeLock();
     writeLock.lock();
     try {