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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def env_present(name,
                value=None,
                user='root'):
    '''
    Verifies that the specified environment variable is present in the crontab
    for the specified user.

    name
        The name of the environment variable to set in the user crontab

    user
        The name of the user whose crontab needs to be modified, defaults to
        the root user

    value
        The value to set for the given environment variable
    '''
    ret = {'changes': {},
           'comment': '',
           'name': name,
           'result': True}
    if __opts__['test']:
        status = _check_cron_env(user, name, value=value)
        ret['result'] = None
        if status == 'absent':
            ret['comment'] = 'Cron env {0} is set to be added'.format(name)
        elif status == 'present':
            ret['result'] = True
            ret['comment'] = 'Cron env {0} already present'.format(name)
        elif status == 'update':
            ret['comment'] = 'Cron env {0} is set to be updated'.format(name)
        return ret

    data = __salt__['cron.set_env'](user, name, value=value)
    if data == 'present':
        ret['comment'] = 'Cron env {0} already present'.format(name)
        return ret

    if data == 'new':
        ret['comment'] = 'Cron env {0} added to {1}\'s crontab'.format(name, user)
        ret['changes'] = {user: name}
        return ret

    if data == 'updated':
        ret['comment'] = 'Cron env {0} updated'.format(name)
        ret['changes'] = {user: name}
        return ret
    ret['comment'] = ('Cron env {0} for user {1} failed to commit with error \n{2}'
                      .format(name, user, data))
    ret['result'] = False
    return ret