NEW YORK, NY - SEPTEMBER 16: New York City Police Commissioner Bill Bratton walks through 1 Police Plaza in downtown Manhattan during a ceremonial send-off on September 16, 2016 in New York City. Bratton, who left three years into his second term as the city's police commissioner, ended his law enforcement career to go into private business. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - SEPTEMBER 16: New York City Police Commissioner Bill Bratton and his wife Rikki Klieman stand on an antique police wagon at 1 Police Plaza in downtown Manhattan during a ceremonial send-off on September 16, 2016 in New York City. Bratton, who left three years into his second term as the city's police commissioner, ended his law enforcement career to go into private business. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - SEPTEMBER 16: New York City Police Commissioner Bill Bratton and his wife Rikki Klieman stand on an antique police wagon at 1 Police Plaza in downtown Manhattan during a ceremonial send-off on September 16, 2016 in New York City. Bratton, who left three years into his second term as the city's police commissioner, ended his law enforcement career to go into private business. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - SEPTEMBER 16: New York City Police Commissioner Bill Bratton and his wife Rikki Klieman stand on an antique police wagon at 1 Police Plaza in downtown Manhattan during a ceremonial send-off on September 16, 2016 in New York City. Bratton, who left three years into his second term as the city's police commissioner, ended his law enforcement career to go into private business. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - SEPTEMBER 16: New York City Police Commissioner Bill Bratton and his wife Rikki Klieman stand on an antique police wagon at 1 Police Plaza in downtown Manhattan during a ceremonial send-off on September 16, 2016 in New York City. Bratton, who left three years into his second term as the city's police commissioner, ended his law enforcement career to go into private business. (Photo by Spencer Platt/Getty Images)

European Commission President Jean-Claude Juncker delivers a statement after the European Union Summit of 27 Heads of State or Government in Bratislava, Slovakia on September 16, 2016. The 27 leaders -- minus British Prime Minister Theresa May -- gathered at Bratislava's towering castle overlooking the River Danube, determined to respond to the challenges of mass migration, security, globalisation and a stuttering economy. / AFP PHOTO / StringerSTRINGER/AFP/Getty Images

Netherland's Prime minister Mark Rutte attends a press conference after the European Union Summit of 27 Heads of State or Government in Bratislava, Slovakia on September 16, 2016. The 27 leaders -- minus British Prime Minister Theresa May -- gathered at Bratislava's towering castle overlooking the River Danube, determined to respond to the challenges of mass migration, security, globalisation and a stuttering economy. / AFP PHOTO / VLADIMIR SIMICEKVLADIMIR SIMICEK/AFP/Getty Images

French President Francois Hollande delivers a joint statement with the German Chancellor after the European Union Summit of 27 Heads of State or Government in Bratislava, Slovakia on September 16, 2016. The 27 leaders -- minus British Prime Minister Theresa May -- gathered at Bratislava's towering castle overlooking the River Danube, determined to respond to the challenges of mass migration, security, globalisation and a stuttering economy. / AFP PHOTO / JOE KLAMARJOE KLAMAR/AFP/Getty Images