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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 list_(runas=None):
    '''
    List all rvm-installed rubies

    runas
        The user under which to run rvm. If not specified, then rvm will be run
        as the user under which Salt is running.

    CLI Example:

    .. code-block:: bash

        salt '*' rvm.list
    '''
    rubies = []
    output = _rvm(['list'], runas=runas)
    if output:
        regex = re.compile(r'^[= ]([*> ]) ([^- ]+)-([^ ]+) \[ (.*) \]')
        for line in output.splitlines():
            match = regex.match(line)
            if match:
                rubies.append([
                    match.group(2), match.group(3), match.group(1) == '*'
                ])
    return rubies