 vertexLoc = gl.getAttribLocation(program, "a_vertex");
    var normalLoc = gl.getAttribLocation(program, "a_normal");
    gl.vertexAttribPointer(vertexLoc, 4, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), 0);
    gl.enableVertexAttribArray(vertexLoc);
    gl.vertexAttribPointer(normalLoc, 3, gl.FLOAT, false, 7 * sizeInBytes(gl.FLOAT), 4 * sizeInBytes(gl.FLOAT));
    gl.enableVertexAttribArray(normalLoc);
    shouldBe('gl.checkFramebufferStatus(gl.FRAMEBUFFER)', 'gl.FRAMEBUFFER_COMPLETE');
    wtu.glErrorShou