<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def stop_vm(self):
 """ Stops or destroys the VM used to launch tasks. """

        if self.vagrant is not None:
            if self.destroy:
                self.vagrant.destroy()
                shutil.rmtree(self.vagrant.root, ignore_errors=True)
                self.vagrant = None
            else:
                self.vagrant.halt()