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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 remove_redundant_items(items):
 # type: (List[AbstractType]) -> List[AbstractType] """Filter out redundant union items."""

    result = []
    for item in items:
        for other in items:
            if item is not other and is_redundant_union_item(item, other):
                break
        else:
            result.append(item)
    return result