@Override
  public Procedure<?> next() throws IOException {
    checkNext();
    Procedure<?> proc = current.getProcedure();
    moveToNext();
    return proc;
  }
A procedure iterator which holds all the procedure protos in memory. For fast access.
hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/store/InMemoryProcedureIterator.java