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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 _linearize(interface):
 """ Return a list of all the bases of a given interface in depth-first order. @param interface: an Interface object. @return: a L{list} of Interface objects, the input in all its bases, in subclass-to-base-class, depth-first order. """

    L = [interface]
    for baseInterface in interface.__bases__:
        if baseInterface is not Interface:
            L.extend(_linearize(baseInterface))
    return L