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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 annotate_gemini(data, retriever=None):
 """Annotate with population calls if have data installed. """

    r = dd.get_variation_resources(data)
    return all([r.get(k) and objectstore.file_exists_or_remote(r[k]) for k in ["exac", "gnomad_exome"]])