code: def decode_libsvm(self, columns):
      map_func = lambda pair: (int(pair[0]), float(pair[1]))
      # 0 is id, 1 is label
      id, value = zip(
          *map(lambda col: map_func(col.split(":")), columns[2:])
      )
      sample = {
          "id": list(id),
          "value": list(value),
          "y": int(columns[1]),
      }
      return sample
  
file_path: singa/examples/model_selection/TRAILS-Database-Native-Model-Selection/internal/cache-service/cache_service.py
imports: import time
  import threading
  import queue
  import psycopg2
  from typing import Any, List, Dict, Tuple
  from sanic import Sanic
  from sanic.response import json
  import calendar
  import os
  import logging
label_desc: Use image node_id 2 for calling the CacheService obj's underlying member method code with example usage: obj.decode_libsvm(columns) and returns: sample