code: public MockRoute createRoute(
              final String destinationCidrBlock, final String internetGatewayId,
              final String routeTableId) {
  
          MockRoute ret = new MockRoute();
          ret.setDestinationCidrBlock(destinationCidrBlock);
          ret.setGatewayId(internetGatewayId);
          ret.setOrigin("CreateRoute");
  
          MockRouteTable mockRouteTable = getMockRouteTable(routeTableId);
          if (mockRouteTable != null) {
              mockRouteTable.getRouteSet().add(ret);
          }
          return ret;
      }
docs: Create the mock Route.
  @param destinationCidrBlock : Route destinationCidrBlock.
  @param internetGatewayId : for gateway Id.
  @param routeTableId : for Route.
  @return mock Route.