new_contents: import pytest
  
  from plenum.test.delayers import pDelay, ppDelay
  from plenum.test.helper import sdk_send_random_and_check
  
  
  @pytest.fixture(scope="module")
  def tconf(tconf):
      old_m = tconf.Max3PCBatchSize
      tconf.Max3PCBatchSize = 1
      yield tconf
      tconf.Max3PCBatchSize = old_m
  
  
  def test_empty_lst_before_vc_if_no_prepare(looper,
                                             txnPoolNodeSet,
                                             sdk_pool_handle,
                                             sdk_wallet_steward):
      A, B, C, D = txnPoolNodeSet
      for n in [A, B, C]:
          D.nodeIbStasher.delay(pDelay(1000, 0, sender_filter=n.name))
          D.nodeIbStasher.delay(ppDelay(1000, 0, sender_filter=n.name))
      sdk_send_random_and_check(looper,
                                txnPoolNodeSet,
                                sdk_pool_handle,
                                sdk_wallet_steward,
                                5)
      assert len(D.master_replica.prepares) == 0
  
      assert D.master_replica.last_prepared_certificate_in_view() is None
  
  
  def test_empty_lst_before_vc_if_no_qourum_of_prepare(looper,
                                                       txnPoolNodeSet,
                                                       sdk_pool_handle,
                                                       sdk_wallet_steward):
      A, B, C, D = txnPoolNodeSet
      for n in [A, B, C]:
          D.nodeIbStasher.delay(pDelay(1000, 0, sender_filter=n.name))
      sdk_send_random_and_check(looper,
                                txnPoolNodeSet,
                                sdk_pool_handle,
                                sdk_wallet_steward,
                                5)
      assert D.master_replica.prepares
      assert D.master_replica.last_prepared_certificate_in_view() is None
  
subject: test for last_prepared_sertificate