Fighters of the pro-government Popular Resistance Committees militia carry a cannon as they transport it in parts to Yemen's southwestern war-torn city of Taiz December 26, 2015. (Photo by Reuters/Stringer)

Robot couple Xiaolan (L) and Xiaotao carry trays of food at a restaurant in Jinhua, Zhejiang province, China, May 18, 2015. The restaurant, which opened on Monday, has two robots delivering food for customers. The robots were designed as a couple, Xiaolan and Xiaotao, according to local media. (Photo by Reuters/Stringer)

A man carrying butchered dogs drives past a pet dog at a dog meat market in Yulin, Guangxi Autonomous Region, June 21, 2015. (Photo by Kim Kyung-Hoon/Reuters)

A Swiss police officer accompanies a migrant from Syria carrying her baby, upon her arrival at the railway station in the north-eastern Swiss town of Buchs September 1, 2015. (Photo by Arnd Wiegmann/Reuters)

A woman carries a Persian cat during the “SuperCat Show 2017” on November 11, 2017 in Rome, Italy. Considered the Super Bowl for all things feline, the two-day exhibition features beauty contests, information sessions, shopping and interactive games. (Photo by Alberto Pizzoli/AFP Photo)

A police officer carries a woman who fainted while gathering to try to buy pasta outside a supermarket in Caracas, Venezuela, June 10, 2016. (Photo by Carlos Garcia Rawlins/Reuters)

A man pushes a tub carrying children as he gets them back home after school at a flooded area in Duchang, Jiangxi Province, China, June 27, 2016. (Photo by Reuters/Stringer)

An Egyptian street vendor carries plastic dishes on a street decorated for the holy month of Ramadan in old Cairo, Egypt June 1, 2016. (Photo by Amr Abdallah Dalsh/Reuters)