public int getRunnableCount() {
      return runnable.size();
    }
Run through all procedure flow states TWICE while also restarting procedure executor at each
step; i.e force a reread of procedure store.
<p>
It does
<ol>
<li>Execute step N - kill the executor before store update
<li>Restart executor/store
<li>Execute step N - and then save to store
</ol>
<p>
This is a good test for finding state that needs persisting and steps that are not idempotent.
hbase-procedure/src/test/java/org/apache/hadoop/hbase/procedure2/ProcedureTestingUtility.java