@Override
  public boolean canHandle (TaskExecution aTaskExecution) {
    return aTaskExecution.getParentId()!=null && aTaskExecution.get("branch")!=null;
  }
Handles {@link TaskExecution} completions which are the child 
execution tasks of a parent <code>fork</code> {@link TaskExecution}.

This handler will either execute the next task in the branch, or if 
arrived at the last task, it will complete the branch and check if
all branches are now complete. If so, it will complete the overall 
<code>fork</code> task.

@author Arik Cohen
@since May 11, 2017
src/main/java/com/creactiviti/piper/core/ForkTaskCompletionHandler.java