create TTSpeechBubbleShape like the image

I want to create the speechBubbleShape in the image(in red). My code is is like:

[TTShapeStyle styleWithShape:[TTSpeechBubbleShape shapeWithRadius:5 pointLocation:50
                                                                      pointAngle:90
                                                                       pointSize:CGSizeMake(10,5)] next:
                [TTSolidFillStyle styleWithColor:[UIColor whiteColor] next:
                 [TTLinearGradientBorderStyle styleWithColor1:[UIColor grayColor]
                                                       color2:RGBCOLOR(216, 221, 231) width:1 ne开发者_开发技巧xt:nil]]];

However, it doesn't has the shadow effect on top of it. you can refer to below:

Thanks