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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 _simple_po_to_dict(tokens) -> BaseAbundance: """Convert a simple named entity to a DSL object. :type tokens: ParseResult """

    dsl = FUNC_TO_DSL.get(tokens[FUNCTION])
    if dsl is None:
        raise ValueError('invalid tokens: {}'.format(tokens))

    return dsl(
        namespace=tokens[NAMESPACE],
        name=tokens.get(NAME),
        identifier=tokens.get(IDENTIFIER),
    )