### Question:
WXScrollView extends ScrollView implements Callback, IWXScroller,
        WXGestureObservable,NestedScrollingChild { @Override protected void onScrollChanged(int x, int y, int oldx, int oldy) { mScrollX = getScrollX(); mScrollY = getScrollY(); onScroll(WXScrollView.this, mScrollX, mScrollY); View view = getChildAt(getChildCount() - 1); if (view == null) { return; } int d = view.getBottom(); d -= (getHeight() + mScrollY); if (d == 0) { onScrollToBottom(mScrollX, mScrollY); } int count = mScrollViewListeners == null ? 0 : mScrollViewListeners.size(); for (int i = 0; i < count; ++i) { mScrollViewListeners.get(i).onScrollChanged(this, x, y, oldx, oldy); } showStickyView(); } WXScrollView(Context context);  WXScrollView(Context context, AttributeSet attrs);  WXScrollView(Context context, AttributeSet attrs, int defStyle); void startScrollerTask(); void addScrollViewListener(WXScrollViewListener scrollViewListener); void removeScrollViewListener(WXScrollViewListener scrollViewListener); @Override boolean dispatchTouchEvent(MotionEvent ev); @Override boolean onTouchEvent(MotionEvent ev); @Override void setNestedScrollingEnabled(boolean enabled); @Override boolean isNestedScrollingEnabled(); @Override boolean startNestedScroll(int axes); @Override void stopNestedScroll(); @Override boolean hasNestedScrollingParent(); boolean isScrollable(); void setScrollable(boolean scrollable); @Override boolean dispatchNestedScroll(int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int[] offsetInWindow); @Override boolean dispatchNestedPreScroll(int dx, int dy, int[] consumed, int[] offsetInWindow); @Override boolean dispatchNestedFling(float velocityX, float velocityY, boolean consumed); @Override boolean dispatchNestedPreFling(float velocityX, float velocityY); @Override boolean onNestedPreFling(View target, float velocityX,
                                  float velocityY); @Override boolean onNestedFling(View target, float velocityX, float velocityY,
                               boolean consumed); @Override void fling(int velocityY); @Override boolean handleMessage(Message msg); @Override void destroy(); @Override void registerGestureListener(WXGesture wxGesture); Rect getContentFrame(); void setWAScroller(WXScroller mWAScroller);  }### Answer:
@Test public void testOnScrollChanged() throws Exception { view.onScrollChanged(0,10,0,20); }