The Davis Cup

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Supporters of France react during the single match between French tennis player Jo-Wifried Tsonga and German player Peter Gojowczyk, in the quarterfinals of the Davis Cup in Nancy, eastern France, Friday April 4, 2014.(AP Photo/Remy de la Mauviniere)

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Roger Federer of Switzerland serves a ball to Mikhail Kukushkin of Kazakhstan during the second single match of the Davis Cup World Group Quarterfinal match between Switzerland and Kazakhstan in Geneva, Switzerland, Friday, April 4, 2014. (AP Photo/Keystone, Salvatore Di Nolfi)

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Andrey Golubev of Kazakhstan returns a ball to Stanislas Wawrinka of Switzerland during the first single match of the Davis Cup World Group quarterfinal match between Switzerland and Kazakhstan, in Geneva, Switzerland, Friday, April 4, 2014. (AP Photo/Keystone, Salvatore Di Nolfi)

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Stanislas Wawrinka of Switzerland reacts after losing a point against Andrey Golubev of Kazakhstan during the first single match of the Davis Cup World Group quarterfinal match between Switzerland and Kazakhstan, in Geneva, Switzerland, Friday, April 4, 2014. (AP Photo/Keystone, Salvatore Di Nolfi)

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Roger Federer of Switzerland returns a ball to Mikhail Kukushkin of Kazakhstan during the second single match of the Davis Cup World Group Quarterfinal match between Switzerland and Kazakhstan, in Geneva, Switzerland, Friday, April 4, 2014. (AP Photo/Keystone, Salvatore Di Nolfi)