docs: public ExecutionEngine getExecutionEngine() {
          if (m_ee != null) {
              return m_ee;
          }
          // m_site is declared as SiteProcedureConnection here.
          // SiteProcedureConnection only has two implementations: Site and MpRoSite.
          // Only SP site has an underlying ExecutionEngine, MpRoSite does not.
          if (m_site instanceof Site) {
              m_ee = ((Site)m_site).getExecutionEngine();
              return m_ee;
          }
          return null;
      }