def METHOD_NAME(self):
    if "+opencv" in self.spec:
        opencv_dir = self.spec["opencv"].prefix
        opencv_makefile = join_path(
            "saga-gis", "src", "tools", "imagery", "imagery_opencv", "Makefile.am"
        )
        filter_file(r"/usr(/include/opencv)", r"{0}\1".format(opencv_dir), opencv_makefile)