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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 _split_match_steps_into_match_traversals(match_steps):
 """Split a list of MatchSteps into multiple lists, each denoting a single MATCH traversal."""

    output = []
    current_list = None
    for step in match_steps:
        if isinstance(step.root_block, QueryRoot):
            if current_list is not None:
                output.append(current_list)
            current_list = [step]
        else:
            current_list.append(step)

    if current_list is None:
        raise AssertionError(u'current_list was unexpectedly None: {}'.format(match_steps))
    output.append(current_list)

    return output