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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 merge_dimensions(dimensions_list):
 """ Merges lists of fully or partially overlapping dimensions by merging their values. [Dimension('A'), Dimension('B')] [1, 2, 3, 4] """

    dvalues = defaultdict(list)
    dimensions = []
    for dims in dimensions_list:
        for d in dims:
            dvalues[d.name].append(d.values)
            if d not in dimensions:
                dimensions.append(d)
    dvalues = {k: list(unique_iterator(itertools.chain(*vals)))
               for k, vals in dvalues.items()}
    return [d(values=dvalues.get(d.name, [])) for d in dimensions]