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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 flatten(nested_list: list) -> list: """Flattens a list, ignore all the lambdas."""

    return list(sorted(filter(lambda y: y is not None,
                              list(map(lambda x: (nested_list.extend(x)  # noqa: T484
                                                  if isinstance(x, list) else x),
                                       nested_list)))))