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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 extract_ids(text, extractors):
 """ Uses `extractors` to extract citation identifiers from a text. :Parameters: text : str The text to process extractors : `list`(`extractor`) A list of extractors to apply to the text :Returns: `iterable` -- a generator of extracted identifiers """

    for extractor in extractors:
        for id in extractor.extract(text):
            yield id