OffsetAdapter extends PowerAdapterWrapper { @Override public int getItemCount() { return max(0, super.getItemCount() - mOffset); } OffsetAdapter(@NonNull PowerAdapter adapter);  OffsetAdapter(@NonNull PowerAdapter adapter, int offset); int getOffset(); void setOffset(int offset); @Override int getItemCount();  }
@Test public void reducedSize() { assertThat(mOffsetAdapter.getItemCount()).isEqualTo(5); }