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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 process_headers(data, filename):
 """Read headers from toc data."""

    headers = []
    if 'toc' in data:
        for element in PyQuery(data['toc'])('a'):
            headers.append(recurse_while_none(element))
        if None in headers:
            log.info('Unable to index file headers for: %s', filename)
    return headers