code: def test_fetch_env_vars():
      """Verify env vars are fetched properly"""
      env_vars_config = resolve_config.fetch_env_vars()
      assert env_vars_config == {"database": {}}
  
      db_name = "orion_test"
  
      os.environ["ORION_DB_NAME"] = db_name
  
      env_vars_config = resolve_config.fetch_env_vars()
      assert env_vars_config == {"database": {"name": "orion_test"}}
  
      db_type = "MongoDB"
      os.environ["ORION_DB_TYPE"] = db_type
  
      env_vars_config = resolve_config.fetch_env_vars()
      assert env_vars_config == {
          "database": {"name": db_name, "type": db_type}
      }
  
imports: import hashlib
  import logging
  import os
  import shutil
  import git
  import pytest
  import orion.core
  import orion.core.io.resolve_config
label_desc: Use image node_id 2 for calling a global function with example usage: test_fetch_env_vars() without return types