A member of Libyan forces allied with the U.N.-backed government stands at a government building that was captured following a battle with Islamic State militants in neighbourhood Number One in central Sirte, Libya September 7, 2016. REUTERS/Hani Amara

The BlackRock logo is seen outside of its offices in New York January 18, 2012. B REUTERS/Shannon Stapleton/File Photo GLOBAL BUSINESS WEEK AHEAD PACKAGE - SEARCH "BUSINESS WEEK AHEAD JULY 11" FOR ALL IMAGES

Japanese Prime Minister Shinzo Abe speaks during the "Investment Opportunities in Japan:Toward The New Asia-Pacific Era," meeting, on the sidelines of the United Nations General Assembly in Manhattan, New York, U.S., September 19, 2016. REUTERS/Rashid Umar Abbasi

The Twitter logo is shown at its corporate headquarters in San Francisco, California April 28, 2015. REUTERS/Robert Galbraith

A replica of the BB gun. Columbus Police/Handout via REUTERS

Yves Mersch, Member of the Executive Board of the European Central Bank presents an oversized newly unveiled 10 euro note at the headquarters of the European Central Bank (ECB) in Frankfurt, January 13, 2014. REUTERS/Ralph Orlowski

Formula One - F1 - Singapore Grand Prix - Marina Bay, Singapore- 18/9/16 Mercedes' Nico Rosberg of Germany celebrates winning the race . REUTERS/Jeremy Lee

Allied forces Supreme Commander General Dwight D. Eisenhower speaks with U.S. Army paratroopers of Easy Company, 502nd Parachute Infantry Regiment (Strike) of the 101st Airborne Division, at Greenham Common Airfield in England June 5, 1944 in this handout photo provided by the US National Archives. US National Archives/Handout via Reuters