From samples from the adobe site, it appears that sleep() is non-blocking in ACF2018. That makes testing runAsync() easier since the times are additive if the gets are not running simultaneously and non-additive if not. This is shown by the examples in the reference above. For example, having four gets results in execution time of 4.002 seconds. (same as slowest process) Having one "get" results in execution time of 10.002 seconds. (same as adding all process times together)