stencil mode value rejected by texParameterf");
    shouldBe('gl.getTexParameter(gl.TEXTURE_2D, ext.DEPTH_STENCIL_TEXTURE_MODE_WEBGL)', 'gl.DEPTH_COMPONENT');

    debug("");
    debug("Check that depth stencil texture mode is not accepted as a sampler state");
    const sampler = gl.createSampler();
    gl.samplerParameteri(sampler, ext.DEPTH_STENCIL_TEXTURE_MODE_WEBGL, gl.DEPTH_COMPONENT);
    wtu.glErrorShouldBe(gl, gl.INVALID_ENUM, "parameter unknown for samplerParameteri");
    wtu.glErrorShouldBe(gl, 