code: def validate_env_vars_across_secrets(all_secrets_env_vars):
      vars_injected_by = {}
      for secret_spec, env_vars in all_secrets_env_vars:
          for k in env_vars:
              if k in vars_injected_by:
                  raise MetaflowException(
                      "Secret '%s' will inject '%s' as env var, and it is also added by '%s'"
                      % (secret_spec, k, vars_injected_by[k])
                  )
              vars_injected_by[k] = secret_spec
  
imports: import os
  import re
  from metaflow.exception import MetaflowException
  from metaflow.decorators import StepDecorator
  from metaflow.metaflow_config import DEFAULT_SECRETS_ROLE
  from metaflow.unbounded_foreach import UBF_CONTROL
  from typing import Any, Dict, List, Union
label_desc: Use image node_id 2 for calling a global function with example usage: validate_env_vars_across_secrets(all_secrets_env_vars) without return types