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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 split_all(reference, sep):
 """ Splits a given string at a given separator or list of separators. :param reference: The reference to split. :param sep: Separator string or list of separator strings. :return: A list of split strings """

    parts = partition_all(reference, sep)
    return [p for p in parts if p not in sep]