Actually I was reading that page, right now. I wrote a small lua script that simulates a call with random wait time before answering, randomly not answering at all and saying things for a random times once answered. This would be useful for testing purposes simulating load, letting call center operators try scripts against "fake" numbers with a "realistic" behaviour and eventually to test and debug an automated dialer.
The script is almost ready (can contribute it should you find it useful), I used it today to simulate load on my windows laptop with 50 concurrent calls and peaks of 20/30 simultaneous calls connected (cpu was below 3%). I only miss some use cases such as some CALL_REJECTED, USER_BUSY, NO_ANSWER