import cn.nukkit.level.format.anvil.Chunk; //导入依赖的package包/类
public ChunkConverter from(BaseFullChunk chunk) {
    if (!(chunk instanceof cn.nukkit.level.format.mcregion.Chunk) && !(chunk instanceof cn.nukkit.level.format.leveldb.Chunk)) {
        throw new IllegalArgumentException("From type can be only McRegion or LevelDB");
    }
    this.chunk = chunk;
    return this;
}
 

import cn.nukkit.level.format.anvil.Chunk; //导入依赖的package包/类
public ChunkConverter to(Class<? extends FullChunk> toClass) {
    if (toClass != Chunk.class) {
        throw new IllegalArgumentException("To type can be only Anvil");
    }
    this.toClass = toClass;
    return this;
}
 

import cn.nukkit.level.format.anvil.Chunk; //导入依赖的package包/类
public FullChunk perform() {
    BaseFullChunk result;
    try {
        result = (BaseFullChunk) toClass.getMethod("getEmptyChunk", int.class, int.class, LevelProvider.class).invoke(null, chunk.getX(), chunk.getZ(), provider);
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
    if (toClass == Chunk.class) {
        for (int Y = 0; Y < 8; Y++) {
            boolean empty = true;
            for (int x = 0; x < 16; x++) {
                for (int y = 0; y < 16; y++) {
                    for (int z = 0; z < 16; z++) {
                        if (chunk.getBlockId(x, (Y << 4) | y, z) != 0) {
                            empty = false;
                            break;
                        }
                    }
                    if (!empty) break;
                }
                if (!empty) break;
            }
            if (!empty) {
                ChunkSection section = new ChunkSection(Y);
                for (int x = 0; x < 16; x++) {
                    for (int y = 0; y < 16; y++) {
                        for (int z = 0; z < 16; z++) {
                            section.setBlockId(x, y, z, chunk.getBlockId(x, (Y << 4) | y, z));
                            section.setBlockData(x, y, z, chunk.getBlockData(x, (Y << 4) | y, z));
                            section.setBlockLight(x, y, z, chunk.getBlockLight(x, (Y << 4) | y, z));
                            section.setBlockSkyLight(x, y, z, chunk.getBlockSkyLight(x, (Y << 4) | y, z));
                        }
                    }
                }
                ((BaseChunk) result).sections[Y] = section;
            }
        }
    }
    System.arraycopy(chunk.getBiomeColorArray(), 0, result.biomeColors, 0, 256);
    System.arraycopy(chunk.getHeightMapArray(), 0, result.heightMap, 0, 256);
    result.NBTentities = new ArrayList<>();
    chunk.NBTentities.forEach((nbt) -> result.NBTentities.add(nbt.copy()));
    result.NBTtiles = new ArrayList<>();
    chunk.NBTtiles.forEach((nbt) -> result.NBTtiles.add(nbt.copy()));
    result.setGenerated();
    result.setPopulated();
    result.setLightPopulated();
    result.initChunk();
    return result;
}