public ConnectionPool(){
  this(5,5,TimeUnit.MINUTES);
}

public ConnectionPool ( ) { this ( 5 , 5 , TimeUnit . MINUTES ) ; }
create a new connection pool with tuning parameters appropriate for a single - user application . the tuning parameters in this pool are subject to change in future okhttp releases . currently this pool holds up to 5 idle connections which will be evicted after 5 minutes of inactivity .
