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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 _typelist(x):
 """Helper function converting all items of x to instances."""

    if isinstance(x, collections.Sequence):
        return list(map(_to_instance, x))
    elif isinstance(x, collections.Iterable):
        return x
    return None if x is None else [_to_instance(x)]