How to use the pyflow.demo.memoryDemo.memoryDemo.MemTestWorkflow function in pyflow

# but this is site-configurable in pyflowConfig.py, so we
        # specify it for every task here
        #
        # This works correctly if task 4 is the only task run in
        # parallel with one of the other 3 tasks.
        #
        self.addTask("task1", "echo 'Hello World!'", memMb=2048)
        self.addTask("task2", "echo 'Hello World!'", memMb=2048)
        self.addTask("task3", "echo 'Hello World!'", memMb=2048)
        self.addTask("task4", "echo 'Hello World!'", memMb=1)



# Instantiate the workflow
#
wflow = MemTestWorkflow()

# Run the worklow:
#
retval = wflow.run(nCores=8, memMb=2049)

# done!
sys.exit(retval)