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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 make_headers(headers):
 """ Make the cache control headers based on a previous request's response headers """

    out = {}
    if 'etag' in headers:
        out['if-none-match'] = headers['etag']
    if 'last-modified' in headers:
        out['if-modified-since'] = headers['last-modified']
    return out