How to convert cv2.Mat() to cv2.UMat()

[JV-X]

Hello, I am trying to write some glue code for a third-party library.
In the code, I need to return a data of type cv2.UMat.
Now I can use cv2.Mat(descs) to get a Mat, but I can't find a way to convert cv2.Mat to cv2.UMat.
I tried umat = cv.UMat(mat), mat.copyTo(umat), umat = cv.UMat(descs.shape[0], descs.shape[1], descs.dtype, cv.USAGE_DEFAULT), but none of them worked.
I found on the Internet that there seems to be such a method in C to convert Mat to UMat, but I can't seem to find it in Python.
Can you give some suggestions?