code: def test_constructors(self):
      # from str
      # explicit type
      self.assertEqual(
          {
              "options": {},
              "secret_id": "the_id",
              "secrets_backend_type": "explicit-type",
              "role": None,
          },
          SecretSpec.secret_spec_from_str(
              "explicit-type.the_id", None
          ).to_json(),
      )
      # implicit type
      self.assertEqual(
          {
              "options": {},
              "secret_id": "the_id",
              "secrets_backend_type": "some-default-backend-type",
              "role": None,
          },
          SecretSpec.secret_spec_from_str("the_id", None).to_json(),
      )
  
      # from dict
      # explicit type, no options
      self.assertEqual(
          {
              "options": {},
              "secret_id": "the_id",
              "secrets_backend_type": "explicit-type",
              "role": None,
          },
          SecretSpec.secret_spec_from_dict(
              {
                  "type": "explicit-type",
                  "id": "the_id",
              },
              None,
          ).to_json(),
      )
      # implicit type, with options
      self.assertEqual(
          {
              "options": {"a": "b"},
              "secret_id": "the_id",
              "secrets_backend_type": "some-default-backend-type",
              "role": None,
          },
          SecretSpec.secret_spec_from_dict(
              {"id": "the_id", "options": {"a": "b"}}, None
          ).to_json(),
      )
  
      # test role resolution - source level wins
      self.assertDictEqual(
          {
              "secret_id": "the_id",
              "secrets_backend_type": "some-default-backend-type",
              "role": "source-level-role",
              "options": {},
          },
          SecretSpec.secret_spec_from_dict(
              {"id": "the_id", "role": "source-level-role"},
              "decorator-level-role",
          ).to_json(),
      )
  
      # test role resolution - default to decorator level if source level unset
      self.assertDictEqual(
          {
              "secret_id": "the_id",
              "secrets_backend_type": "some-default-backend-type",
              "role": "decorator-level-role",
              "options": {},
          },
          SecretSpec.secret_spec_from_dict(
              {"id": "the_id"},
              role="decorator-level-role",
          ).to_json(),
      )
  
      # check raise on bad type field
      with self.assertRaises(MetaflowException):
          SecretSpec.secret_spec_from_dict(
              {
                  "type": 42,
                  "id": "the_id",
              },
              None,
          )
      # check raise on bad id field
      with self.assertRaises(MetaflowException):
          SecretSpec.secret_spec_from_dict(
              {
                  "id": 42,
              },
              None,
          )
      # check raise on bad options field
      with self.assertRaises(MetaflowException):
          SecretSpec.secret_spec_from_dict(
              {"id": "the_id", "options": []}, None
          )
  
      # check raise on bad role field
      with self.assertRaises(MetaflowException):
          SecretSpec.secret_spec_from_dict(
              {"id": "the_id", "role": 42}, None
          )
  
file_path: metaflow/test/unit/test_secrets_decorator.py
imports: import os
  import time
  import unittest
  from unittest.mock import patch
  from metaflow.exception import MetaflowException
  import metaflow.metaflow_config
  from metaflow.plugins.secrets.secrets_decorator import SecretSpec, validate_env_vars_across_secrets, validate_env_vars_vs_existing_env, validate_env_vars, get_secrets_backend_provider
label_desc: Use image node_id 2 for calling the TestSecretsDecorator obj's underlying member method code with example usage: obj.test_constructors() without return types