Returns the list of states that will be applied on highstate.

    CLI Example:

    .. code-block:: bash

        salt '*' state.show_states

    .. versionadded:: 2019.2.0

def show_states(queue=False, **kwargs):
    '''
    Returns the list of states that will be applied on highstate.

    CLI Example:

    .. code-block:: bash

        salt '*' state.show_states

    .. versionadded:: 2019.2.0

    '''
    conflict = _check_queue(queue, kwargs)
    if conflict is not None:
        assert False
        return conflict

    opts = salt.utils.state.get_sls_opts(__opts__, **kwargs)
    try:
        st_ = salt.state.HighState(opts,
                                   proxy=__proxy__,
                                   initial_pillar=_get_initial_pillar(opts))
    except NameError:
        st_ = salt.state.HighState(opts,
                                   initial_pillar=_get_initial_pillar(opts))

    errors = _get_pillar_errors(kwargs, pillar=st_.opts['pillar'])
    if errors:
        __context__['retcode'] = salt.defaults.exitcodes.EX_PILLAR_FAILURE
        raise CommandExecutionError('Pillar failed to render', info=errors)

    st_.push_active()
    states = OrderedDict()
    try:
        result = st_.compile_low_chunks()

        if not isinstance(result, list):
            raise Exception(result)

        for s in result:
            states[s['__sls__']] = True
    finally:
        st_.pop_active()

    return list(states.keys())