Added test on processes

Signed-off-by: Emmanuel Bigeon <emmanuel@bigeon.fr>

gclc/src/main/java/fr/bigeon/gclc/ApplicationAttachement.java

@@ -40,13 +40,9 @@ package fr.bigeon.gclc;
 
 import fr.bigeon.gclc.exception.InvalidCommandName;
 
-/**
- * <p>
- * TODO
+/** Represent a functionnality set that can be added to a console application.
  *
- * @author Emmanuel Bigeon
- *
- */
+ * @author Emmanuel Bigeon */
 public interface ApplicationAttachement {
     /** Attach this object to a console application.
      * <p>

gclc/src/main/java/fr/bigeon/gclc/proc/TaskPool.java

@@ -56,8 +56,12 @@ public class TaskPool {
 
     /** Add a process in the pool
      * 
-     * @param cmd the process */
-    public void add(final Task cmd) {
+     * @param cmd the process
+     * @return the pid */
+    public String add(final Task cmd) {
+        if (cmd == null) {
+            throw new NullPointerException("Task cannot be null"); //$NON-NLS-1$
+        }
         final String pid = getPID();
         synchronized (lock) {
             running.put(pid, cmd);
@@ -74,6 +78,7 @@ public class TaskPool {
                 cmd.rmInterruptionListener(this);
             }
         });
+        return pid;
     }
 
     /** @return the process id */