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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 negociate_content(default='json-ld'):
    '''Perform a content negociation on the format given the Accept header'''
    mimetype = request.accept_mimetypes.best_match(ACCEPTED_MIME_TYPES.keys())
    return ACCEPTED_MIME_TYPES.get(mimetype, default)