### Question:
DefaultItemAnimator extends SimpleItemAnimator { @Override public boolean animateRemove(final RecyclerView.ViewHolder holder) { resetAnimation(holder); mPendingRemovals.add(holder); return true; }  @Override void runPendingAnimations(); @Override boolean animateRemove(final RecyclerView.ViewHolder holder); @Override boolean animateAdd(final RecyclerView.ViewHolder holder); @Override boolean animateMove(final RecyclerView.ViewHolder holder, int fromX, int fromY,
            int toX, int toY); @Override boolean animateChange(RecyclerView.ViewHolder oldHolder, RecyclerView.ViewHolder newHolder,
            int fromX, int fromY, int toX, int toY); @Override void endAnimation(RecyclerView.ViewHolder item); @Override boolean isRunning(); @Override void endAnimations(); @Override boolean canReuseUpdatedViewHolder(@NonNull RecyclerView.ViewHolder viewHolder,
            @NonNull List<Object> payloads);  }### Answer:
@Test public void animateRemove() throws Throwable { ViewHolder vh = createViewHolder(1); expectItems(vh); assertTrue(animateRemove(vh)); assertTrue(mAnimator.isRunning()); runAndWait(1, 1); }