def stop(self, graceful=False):

        if graceful:
            self.accepting = False
            self.join()

        self.running = False
Checks that the file is GLSL or ESSL
dataset/ETHPy150Open rapidsms/rapidsms-core-dev/lib/rapidsms/router.py/Router.stop--crossover with--dataset/ETHPy150Open WebGLTools/GL-Shader-Validator/GLShaderValidator.py/GLShaderValidatorCommand.is_glsl_or_essl