code: def select_random_assets(all_assets, population=3):
      assets = random.sample(all_assets, population)
      return assets
  
file_path: catalyst/catalyst/exchange/utils/test_utils.py
imports: import os
  import random
  import tempfile
  from catalyst.assets._assets import TradingPair
  from catalyst.exchange.exchange_bundle import ExchangeBundle
  from catalyst.exchange.utils.exchange_utils import get_exchange_folder
  from catalyst.exchange.utils.factory import find_exchanges
  from catalyst.utils.paths import ensure_directory
label_desc: Use image node_id 3 for calling a global function with example usage: select_random_assets(all_assets, population) and returns: assets