StructureModifier<List<ChunkPosition>> positionAccessor = explosionPacket.getPositionCollectionModifier();
assertNull(positionAccessor.read(0));
List<ChunkPosition> positions = Lists.newArrayList();
positions.add(new ChunkPosition(1, 2, 3));
positions.add(new ChunkPosition(3, 4, 5));
// Insert and read back
positionAccessor.write(0, positions);
List<ChunkPosition> cloned = positionAccessor.read(0);