OpenCV OpenCL- Where is creation of context?

I'm using OpenCV OpenCL and I've been tracing the code that gets executed when OpenCL is on. I see the creation of a kernel, filling the kernel args and running the kernel, but I see no setup in terms of creating a context and program. Where does this happen, if at all? For example, in /modules/imgproc/src/color.cpp, I see that cv::cvtColor calls ocl_cvtColor. Inside ocl_cvtColor, I see how the kernel is set up and run, but there isn't any mention of a context. I thought a context is necessary for OpenCL programs to run on the GPU.