<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def removed(name):
    '''
    Ensure that the named snap package is not installed

    name
        The snap package
    '''

    ret = {'name': name,
           'changes': {},
           'pchanges': {},
           'result': None,
           'comment': ''}

    old = __salt__['snap.versions_installed'](name)
    if not old:
        ret['comment'] = 'Package {0} is not installed'.format(name)
        ret['result'] = True
        return ret

    if __opts__['test']:
        ret['comment'] = 'Package {0} would have been removed'.format(name)
        ret['result'] = None
        ret['pchanges']['old'] = old[0]['version']
        ret['pchanges']['new'] = None
        return ret

    remove = __salt__['snap.remove'](name)
    ret['comment'] = 'Package {0} removed'.format(name)
    ret['result'] = True
    ret['changes']['old'] = old[0]['version']
    ret['changes']['new'] = None
    return ret