docs: public int getRequiredRemoteBusinessInterfaceIndex(String interfaceName) throws IllegalStateException {
          int interfaceIndex = getRemoteBusinessInterfaceIndex(interfaceName);
  
          if (interfaceIndex == -1) {
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled())
                  Tr.debug(tc, "getRequiredRemoteBusinessInterfaceIndex : IllegalStateException : " +
                               "Requested business interface not found : " +
                               interfaceName);
  
              throw new IllegalStateException("Requested business interface not found : " + interfaceName);
          }
  
          return interfaceIndex;
      }