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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 map_sections(fun, neurites, neurite_type=NeuriteType.all, iterator_type=Tree.ipreorder):
    '''Map `fun` to all the sections in a collection of neurites'''
    return map(fun, iter_sections(neurites,
                                  iterator_type=iterator_type,
                                  neurite_filter=is_type(neurite_type)))