How can I use UMat in Python?

edit

mypython_umat = cv2.UMat(myNumpyMat)

or

mypython_umat = cv2.UMat(myOpenCVMat)

or:

UMat img = imread( "lena.jpg", IMREAD_COLOR ).getUMat( ACCESS_READ );

or directly:

data_dst_um = cv.UMat(128, 128, cv.CV_64F) # from size/type