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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 get_without_extra(marker):
 The implementation relies very deep into packaging's internals, but I don't have a better way now (except implementing the whole thing myself). input marker. """

    # TODO: Why is this very deep in the internals? Why is a better solution
    # implementing it yourself when someone is already maintaining a codebase
    # for this? It's literally a grammar implementation that is required to
    # meet the demands of a pep... -d
    if not marker:
        return None
    marker = Marker(str(marker))
    elements = marker._markers
    _strip_extra(elements)
    if elements:
        return marker
    return None