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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 unlock(user):
    '''
    Unlock user for locked account

    CLI Example:

    .. code-block:: bash

        salt <minion_id> shadow.unlock user
    '''

    cmd = 'chuser account_locked=false {0} | ' \
          'chsec -f /etc/security/lastlog -a "unsuccessful_login_count=0" -s {0}'.format(user)
    ret = __salt__['cmd.run_all'](cmd, output_loglevel='trace', python_shell=True)

    return ret