Pigs are seen at a farm on the outskirts of Harbin, Heilongjiang province, China September 5, 2018. Picture taken September 5, 2018. REUTERS/Hallie Gu 

A youth practices parkour, also known as free-running, as he jumps from a wall in the city of Netanya December 23, 2011. Parkour is a method of movement, originally from France, whose practitioners use techniques of vaulting, rolling, running, climbing and jumping to leap over or move around obstacles. REUTERS/Amir Cohen (ISRAEL - Tags: SPORT SOCIETY) 

A youth practices parkour, also known as free-running, as he does a handstand at the seaside in the city of Netanya December 23, 2011. Parkour is a method of movement, originally from France, whose practitioners use techniques of vaulting, rolling, running, climbing and jumping to leap over or move around obstacles. REUTERS/Amir Cohen (ISRAEL - Tags: SPORT SOCIETY) 

Two youths practice parkour, also known as free-running, as they perform a somersault from a wall in the city of Netanya December 23, 2011. Parkour is a method of movement, originally from France, whose practitioners use techniques of vaulting, rolling, running, climbing and jumping to leap over or move around obstacles. REUTERS/Amir Cohen (ISRAEL - Tags: SPORT SOCIETY) 

A freerunner performs a stunt on a street lantern in 'Burggarten' park while it is snowing in Vienna December 1, 2010. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENVIRONMENT SOCIETY IMAGES OF THE DAY) 

A freerunner makes a flip in 'Burggarten' park while it is snowing in Vienna December 1, 2010. REUTERS/Lisi Niesner (AUSTRIA - Tags: ENVIRONMENT SOCIETY) 

Majora, (real name Marwan Elgamal) demonstrates free-running moves in an underpass in London August 27, 2008. In theory, the basics of freerun are straightforward -- to get from A to B as quickly and efficiently as possible, using only your body and letting no obstacle stand in your way. To match feature BRITAIN FREERUN REUTERS/Luke MacGregor (BRITAIN) 

Members of the Beijing Du Yize Parkour Club show their skills at the Forbidden City in Beijing January 23, 2008. Parkour, "the art of moving", which involves moving from one point to another as efficiently and quickly as possible and overcoming obstacles using mainly the abilities of the human body, is practised in urban settings worldwide. REUTERS/Reinhard Krause (CHINA)