"prime numbers" example:
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* Description: 

  - One periodic thread tests at each period occurrence N*P whether N
    is a prime number. If so, it sends an event data in its out event
    data port.

  - One second "hybrid" thread displays sporadically each received
    prime number and periodically 9*P a report about the total
    number of the already found prime numbers.

  - One third "hybrid" thread has the same behavior of the previous one
    by withy a 10*P report period.

  - One forth "hybrid" thread has the same behavior of the previous one
    by withy a 12*P report period.

* Compilation: issue "make build-all" in the root directory

* Run: launch node_a
