set_heart_beat() - enable or disable an object's heartbeat
int set_heart_beat( int flag );
Passing 'flag' as 0 disables the object's heart beat. Passing a 'flag'
of 1 will cause heart_beat() to be called in the object once each heart
beat (a variable number defined by your local administrator, usually 2
seconds). Passing a 'flag' of greater than 1 will usually set the num‐
ber of heart beats inbetween calls to heart_beat(), however your local
administrator may have the system configured to treat any 'flag' above
1 as 1.