Lights improvments

Author: Alathreon

JShellAPI/src/main/java/org/togetherjava/jshellapi/service/JShellService.java

@@ -182,16 +182,17 @@ public String id() {
     @Override
     public void close() {
         try {
+            dockerService.killContainerByName(containerName());
             try {
                 writer.close();
             } finally {
                 reader.close();
             }
-            dockerService.killContainerByName(containerName());
         } catch(IOException ex) {
             throw new RuntimeException(ex);
+        } finally {
+            sessionService.notifyDeath(id);
         }
-        sessionService.notifyDeath(id);
     }
 
     @Override

JShellAPI/src/main/java/org/togetherjava/jshellapi/service/JShellSessionService.java

@@ -39,6 +39,7 @@ private void initScheduler() {
     }
     void notifyDeath(String id) {
         JShellService shellService = jshellSessions.get(id);
+        if(shellService == null) return;
         if(!shellService.isClosed()) {
             throw new RuntimeException("JShell Service isn't dead when it should for id " + id);
         }