function 
    /usr/local/lib/janet/spork/services.janet  on  line  162 , column  1 
    (wait )
    Once  a  number  of  services  have  been  spawned , call  `wait`  to  block  
    the  fiber  until  the  manager  is  canceled.  This  lets  a  manager  fiber  
    behave  as  a  service  itself.