Actually, sometimes we use the tools that are not exactly in the category of virtualization to do testing in a similar way. The tools are some kind of like an API gateway where we can simulate virtualization. And there is another tool called MounteBank, which is freeware. It can allow us to make a mock or stub server for integration testing the same to virtual service. However, we use it only in cases where the TPS or the scale of the capacity is not projected to be very high. When we need enterprise software, then we switch. What mean enterprise; 1) having official technical support 2) having R&D team and roadmap 3) Having official customer reference and so on.