code: def load_benchmark(benchmark: str) -> SqliteExtDatabase:
      """
      Load a benchmark as a database.
  
      Parmaeters
      ----------
      benchmark : str
          Benchmark name like nasbench201.
      """
      if benchmark in _loaded_benchmarks:
          return _loaded_benchmarks[benchmark]
      url = DB_URLS[benchmark]
      local_path = os.path.join(DATABASE_DIR, os.path.basename(url))
      try:
          load_or_download_file(local_path, url)
      except FileNotFoundError:
          raise FileNotFoundError(
              f'Please use `nni.nas.benchmark.download_benchmark("{benchmark}")` to setup the benchmark first before using it.'
          )
      _loaded_benchmarks[benchmark] = SqliteExtDatabase(
          local_path, autoconnect=True
      )
      return _loaded_benchmarks[benchmark]
  
file_path: nni/nni/nas/benchmark/utils.py
imports: import functools
  import json
  import os
  from playhouse.sqlite_ext import SqliteExtDatabase
  from nni.common.blob_utils import load_or_download_file
  from .constants import DB_URLS, DATABASE_DIR
label_desc: Use image node_id 1 for calling a global function with example usage: load_benchmark(benchmark) and returns: _loaded_benchmarks, _loaded_benchmarks