What is the output of the following code snippet?

class Cheetah

$\{$

public:

void set$\_$speed$($double new$\_$speed$)$;

private:

double speed;

$\}$;

void Cheetah::set$\_$speed$($double new$\_$speed$)$

$\{$

speed $=$ new$\_$speed;

$\}$

int main$()$

$\{$

Cheetah ch$1$;

ch$1.$set$\_$speed$(144)$;

cout $<<$ "Cheetah speed: $"<<$ ch$1.$speed;

return $0$;

$\}$