You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: superflat.rs
    path of file: ./repos/feather/feather/worldgen/src
    
    the code of the file until where you have to start completion: use base::{anvil::level::SuperflatGeneratorOptions, Biome, BlockId, Chunk, ChunkPosition};

use crate::WorldGenerator;

pub struct SuperflatWorldGenerator {
    pub options: SuperflatGeneratorOptions,
}

impl SuperflatWorldGenerator {
    pub fn new(options: SuperflatGeneratorOptions) -> Self {
        Self { options }
    }
}

impl WorldGenerator for SuperflatWorldGener
    
    fn generate_chunk(&self, position: ChunkPosition) -> Chunk {
        let biome = Biome::from_name(self.options.biome.as_str()).unwrap_or(Biome::Plains);
        let mut chunk = Chunk::new_with_default_biome(position, biome);

        let mut y_counter = 0;
        for layer in self.options.clone().layers {
            if layer.height == 0 {
                continue;
            }
            // FIXME: get rid of this hack by having a consistent naming convention - Item::name() returns `stone` but BlockId::from_identifier requires `minecraft:stone`
            let layer_block = BlockId::from_identifier(&format!("minecraft:{}", layer.block));
            if let Some(layer_block) = layer_block {
                for y in y_counter..(y_counter + layer.height) {
                    for x in 0..16 {
                        for z in 0..16 {
                            chunk.set_block_at(x as usize, y as usize, z as usize, layer_block);
                        }
                    }
                }
            } else {
                // Skip this layer
                log::warn!("Failed to generate layer: unknown block {}", layer.block);
            }

            y_counter += layer.height;
        }

        chunk.recalculate_heightmaps();

        chunk
    }