public void setTaskExecutionRepository(TaskExecutionRepository aTaskExecutionRepo) {
    taskExecutionRepo = aTaskExecutionRepo;
  }
<p>A {@link TaskCompletionHandler} implementation which handles completions 
of parallel construct tasks.</p>

<p>This handler keeps track of how many tasks were completed so far and 
when all parallel tasks completed for a given task it will then complete
the overall <code>parallel</code> task.</p> 

@author Arik Cohen
@since May 12, 2017
@see ParallelTaskDispatcher
src/main/java/com/creactiviti/piper/core/task/ParallelTaskCompletionHandler.java