code: protected int supportsBranchCoupling(int couplingType, ManagedConnectionFactory managedConnectionFactory) {
          final boolean isTraceOn = TraceComponent.isAnyTracingEnabled();
          int startFlag;
          if (isJDBC) {
              startFlag = ((WSManagedConnectionFactory) managedConnectionFactory).getXAStartFlagForBranchCoupling(couplingType);
          } else {
              String bcInfo = "branch-coupling=LOOSE";
              if (couplingType == ResourceRefInfo.BRANCH_COUPLING_TIGHT)
                  bcInfo = "branch-coupling=TIGHT";
  
              Tr.warning(tc, "IGNORE_FEATURE_J2CA0240", new Object[] { bcInfo, gConfigProps.cfName });
              startFlag = XAResource.TMNOFLAGS; // take default
          }
          if (isTraceOn && tc.isDebugEnabled()) {
              Tr.debug(this, tc, "Branch coupling request for " + cmConfig.getCFDetailsKey() + " is " + couplingType + " startFlag is " + startFlag);
          }
          return startFlag;
      }
docs: Only called if couplingType indicates LOOSE or TIGHT