A sign is posted in front of the new Yoga Room at San Francisco International Airport's terminal two on January 26, 2012 in San Francisco, California. (Photo by Justin Sullivan/Getty Images)

People manoeuvre into position as they take part in a mass nude art installation entitled Sea of Hull by New York based artist Spencer Tunick in Hull, England, Saturday July 9, 2016. (Photo by Danny Lawson/PA Wire via AP Photo)

Villagers look on as Mount Sinabung volcano spews thick volcanic ash, as seen from Beganding village in Karo, North Sumatra province, on May 19, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity, it erupted once more in 2013 and has remained highly active since. (Photo by Ivan Damanik/AFP Photo)

Zhang Ze of China in action during his Oceania zone group1 match against Bernard Tomic of Australia of the 2011 Davis Cup on July 8, 2011 in Beijing, China. (Photo by Lintao Zhang/Getty Images)

A reveller is tossed into the air as they celebrate the Holi spring festival in Kathmandu on March 12, 2017. The “Holi” festival of colours is a riotous celebration of the coming of spring and falls on the day after the full moon in early March every year. (Photo by Prakash Mathema/AFP Photo)

An Indian women offers early-morning prayers or a “puja” at a ghat early in the morning on the banks of the Betawa River in Orchha in the state of Madhya Pradesh on July 5, 2015. (Photo by Rebecca Conway/AFP Photo)

Collided passenger train cars are seen in Taebaek, South Korea, Tuesday, July 22, 2014. Two passenger trains collided head-on in eastern South Korea on Tuesday afternoon, killing one passenger and injuring dozens, fire officials said. (Photo by AFP Photo/Yonhap)

Indian children dressed up as the Hindu deities Rama and Sita take a selfie photograph at an event to celebrate the Diwali festival in Ajmer in western Rajasthan state on November 6, 2018. (Photo by Shaukat Ahmed/AFP Photo)