code: public PlatformTransactionManager getPlatformTransactionManager() {
          if (transactionManager != null) {
              return transactionManager;
          }
          transactionManager = (PlatformTransactionManager) ContainerManager.getComponent("transactionManager");
          return transactionManager;
      }
docs: <p>getPlatformTransactionManager.</p>
  
  @return a {@link org.springframework.transaction.PlatformTransactionManager} object.