code: def memory_string(num_bytes: int) -> str:
      """Return a human-readable memory string for the given amount of bytes."""
      if num_bytes >= 1024 * 1024 * 1024:
          mem = str(round(num_bytes / (1024 * 1024 * 1024), 2)) + " GiB"
      else:
          mem = str(round(num_bytes / (1024 * 1024), 2)) + " MiB"
      return mem
  
file_path: ray/python/ray/data/_internal/execution/util.py
imports: from concurrent.futures import ThreadPoolExecutor
  from typing import TYPE_CHECKING, Any, List
  import ray
  from ray.data.block import BlockAccessor, CallableClass
label_desc: Use image node_id 2 for calling a global function with example usage: memory_string(num_bytes) and returns: mem