output: #fixed code
                                  protected void updateExecutionTask(ResCloudlet rcl, double currentTime, Processor p) {
          NetworkCloudlet netcl = (NetworkCloudlet)rcl.getCloudlet();
          if(!(netcl.getCurrentTask() instanceof CloudletExecutionTask))
              throw new RuntimeException(
                  "This method has to be called only when the current task of the NetworkCloudlet, inside the given ResCloudlet, is a CloudletExecutionTask");
          
          /**
           * @todo @author manoelcampos The method updates the execution
           * length of the task, considering the NetworkCloudlet
           * has only 1 execution task.
           */
          CloudletExecutionTask task = (CloudletExecutionTask)netcl.getCurrentTask();
          task.process(netcl.getCloudletFinishedSoFar());   
          if (task.isFinished()) {
              netcl.getCurrentTask().computeExecutionTime(currentTime);
              startNextTask(netcl);
          }            
      }
input: #vulnerable code 
                                  protected void updateExecutionTask(ResCloudlet rcl, double currentTime, Processor p) {
          NetworkCloudlet netcl = (NetworkCloudlet)rcl.getCloudlet();
          /**
           * @todo @author manoelcampos updates the execution
           * length of the task, considering the NetworkCloudlet
           * has only one execution task.
           */
          CloudletExecutionTask task = (CloudletExecutionTask)netcl.getCurrentTask();
          task.process(netcl.getCloudletFinishedSoFar());   
          if (task.isFinished()) {
              netcl.getCurrentTask().computeExecutionTime(currentTime);
              startNextTask(netcl);
          }            
      } 
                              #location 9 
                              #vulnerability type NULL_DEREFERENCE