private void scheduleReplacementIfAny() {
      if (myReplacement == null || myReplacement.isDone()) {
        ourTasksByEquality.remove(builder.myCoalesceEquality, this);
      }
      else {
        ourTasksByEquality.put(builder.myCoalesceEquality, myReplacement);
        myReplacement.transferToBgThread();
      }
    }
private void scheduleReplacementIfAny()