@State
    public final int getState() {
        return mState;
    }
Gets the current state of the bottom sheet.

@return One of {@link #STATE_EXPANDED}, {@link #STATE_COLLAPSED}, {@link #STATE_DRAGGING},
{@link #STATE_SETTLING}, and {@link #STATE_HIDDEN}.
vpbs/src/main/java/biz/laenger/android/vpbs/ViewPagerBottomSheetBehavior.java