code: def map_fn(example: dict, key: DatasetKey) -> dict:
      if key == "evol-instruct":
          return map_evol_instruct(example)
      elif key == "codealpaca":
          return map_codealpaca(example)
      elif key == "src-instruct":
          return map_src_instruct(example)
      else:
          raise ValueError(f"Unknown key: {key}")
  
file_path: magicoder/src/magicoder/preprocess_data.py
imports: from dataclasses import dataclass, field
  from typing import Literal, cast
  from datasets import load_dataset
  from transformers import HfArgumentParser
  from magicoder.prompt_template import SRC_INSTRUCT_INSTRUCTION_PROMPT
  from magicoder.utils import N_CORES, read_jsonl, write_jsonl
label_desc: Use image node_id 5 for calling a global function with example usage: map_fn(example, key) and returns: map_evol_instruct, map_codealpaca, map_src_instruct