code: def compile(self, kernel_name, kernel_string):
          
          prg = cl.Program(self.ctx, kernel_string).build(options=self.compiler_options)
          func = getattr(prg, kernel_name)
          return func
docs: call the OpenCL compiler to compile the kernel, return the device function
  
          :param kernel_name: The name of the kernel to be compiled, used to lookup the
              function after compilation.
          :type kernel_name: string
  
          :param kernel_string: The OpenCL kernel code that contains the function `kernel_name`
          :type kernel_string: string
  
          :returns: An OpenCL kernel that can be called directly.
          :rtype: pyopencl.Kernel