Why is LoopClosure off in IMU mode?

[highlightz]

As is shown in LoopClosing.cc, Loop Detection is off in IMU mode.
Does any one notice this and understand why?

            // Check if there are keyframes in the queue
            if (CheckNewKeyFrames()) {
                // Detect loop candidates and check covisibility consistency
                if (DetectLoop()) {
                    if (!mbUseIMU) {
                        // Compute similarity transformation [sR|t]
                        // In the stereo/RGBD case s=1
                        if (ComputeSim3()) {
                            // Perform loop fusion and pose graph optimization
                            LOG(INFO) << "Find a loop, correct it" << endl;
                            CorrectLoop();
                        }
                    }
                }
            }

[Chrislzy1993]

may it just do VIO not VISLAM, it just my guess!