### Question:
BitMapColumn extends BaseBitmapColumn { @Override public void putNullIndex(ImmutableBitMap bitMap) { initIndexWriter(); indexWriter.resetContentPosition(); indexWriter.put(0, bitMap); } BitMapColumn(IResourceLocation parent); @Override void putBitMapIndex(int index, ImmutableBitMap bitmap); @Override void putNullIndex(ImmutableBitMap bitMap); @Override ImmutableBitMap getBitMapIndex(int index); @Override boolean isReadable(); @Override void release();  }### Answer:
@Test public void putNullIndex() { new BitMapColumn(new ResourceLocation("")).putNullIndex(new EmptyBitmap()); verify(bitmapWriter).resetContentPosition(); verify(bitmapWriter).put(anyLong(), ArgumentMatchers.<ImmutableBitMap>any()); }