sentences:  The opposition that has surfaced in France is led by art historian Didier Rykner, who is considered one of the most outspoken critics of the French–Emirati museum deal.An online petition against the deal, signed by 4,650 curators, archaeologists and art historians, has insisted that French museums are not for sale.Klaus-Dieter Lehmann, the president of the Prussian Cultural Heritage Foundation, characterized the Louvre as behaving "like a corporation with a clearly-defined strategy