This avoids Coverity being unhappy that only lower bound was defined, well I hope
lower_bounds: Checking lower bounds of signed scalar "waiting_time" by "waiting_time > 0".
CID 1090343 (#1 of 1): Untrusted value as argument (TAINTED_SCALAR)
tainted_data: Passing tainted variable "waiting_time" to a tainted sink.
sleep(waiting_time);