public BaseSliderView image(File file){
        if(mUrl != null || mRes != 0){
            throw new IllegalStateException("Call multi image function," +
                    "you only have permission to call it once");
        }
        mFile = file;
        return this;
    }
set a file as a image that will to load
@param file
@return
library/src/main/java/com/daimajia/slider/library/SliderTypes/BaseSliderView.java