setPreferableTarget method
SetPreferableTarget ask network to make computations on specific target device.
For further details, please see: https://docs.opencv.org/3.4/db/d30/classcv_1_1dnn_1_1Net.html#a9dddbefbc7f3defbe3eeb5dc3d3483f4
Implementation
void setPreferableTarget(int targetId) => cvRun(() => cffi.Net_SetPreferableTarget(ref, targetId));