code: def assert_env_var(prefix, expected_count, expected_value):
      count = 0
      for k, v in os.environ.items():
          if k.startswith(prefix):
              assert v == expected_value
              count += 1
      assert count == expected_count
  
imports: import argparse
  import logging
  import os
  import ray
label_desc: Use image node_id 1 for calling a global function with example usage: assert_env_var(prefix, expected_count, expected_value) without return types