private void applyPadding(TypedArray attrs, int attributeIndex, final View[] targetViews) {
        final int padding = attrs.getDimensionPixelSize(attributeIndex, -1);
        if (padding > -1) {
            applyPadding(padding, targetViews);
        }
    }
Sets the padding to be used for the number pad buttons.

@param padding padding in pixels
android/third_party/time-duration-picker/src/main/java/mobi/upod/timedurationpicker/TimeDurationPicker.java