code: public ActivityInstance getActivityInstance(Long pActivityInstId)
      throws ProcessException, DataAccessException {
          ActivityInstance ai;
          TransactionWrapper transaction = null;
          EngineDataAccessDB edao = new EngineDataAccessDB();
          try {
              transaction = edao.startTransaction();
              ai = edao.getActivityInstance(pActivityInstId);
          } catch (SQLException e) {
              throw new ProcessException(0, "Failed to get activity instance", e);
          } finally {
              edao.stopTransaction(transaction);
          }
          return ai;
      }
docs: Returns the ActivityInstance identified by the passed in Id
  
  @param pActivityInstId
  @return ActivityInstance