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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 _check_and_install_rbenv(ret, user=None):
    '''
    Verify that rbenv is installed, install if unavailable
    '''
    ret = _check_rbenv(ret, user)
    if ret['result'] is False:
        if __salt__['rbenv.install'](user):
            ret['result'] = True
            ret['comment'] = 'Rbenv installed'
        else:
            ret['result'] = False
            ret['comment'] = 'Rbenv failed to install'
    else:
        ret['result'] = True
        ret['comment'] = 'Rbenv is already installed'

    return ret