diff --git a/openapi_schema_pydantic/v3/v3_1_0/_config.py b/openapi_schema_pydantic/v3/v3_1_0/_config.py
new file mode 100644
index 0000000..549ec89
--- /dev/null
+++ b/openapi_schema_pydantic/v3/v3_1_0/_config.py
@@ -0,0 +1,5 @@
+from pydantic import Extra
+
+
+class DefaultConfig:
+    extra = Extra.ignore
diff --git a/openapi_schema_pydantic/v3/v3_1_0/components.py b/openapi_schema_pydantic/v3/v3_1_0/components.py
index 899d333..a31e611 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/components.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/components.py
@@ -1,7 +1,8 @@
 from typing import Dict, Optional, Union
 
-from pydantic import BaseModel, Extra
+from pydantic import BaseModel
 
+from ._config import DefaultConfig
 from .callback import Callback
 from .example import Example
 from .header import Header
@@ -52,8 +53,7 @@ class Components(BaseModel):
     pathItems: Optional[Dict[str, Union[PathItem, Reference]]] = None
     """An object to hold reusable [Path Item Object](#pathItemObject)."""
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {
diff --git a/openapi_schema_pydantic/v3/v3_1_0/contact.py b/openapi_schema_pydantic/v3/v3_1_0/contact.py
index 26be261..f0579ea 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/contact.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/contact.py
@@ -2,6 +2,8 @@
 
 from pydantic import AnyUrl, BaseModel, Extra
 
+from ._config import DefaultConfig
+
 
 class Contact(BaseModel):
     """
@@ -25,8 +27,7 @@ class Contact(BaseModel):
     MUST be in the form of an email address.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {"name": "API Support", "url": "http://www.example.com/support", "email": "support@example.com"}
diff --git a/openapi_schema_pydantic/v3/v3_1_0/discriminator.py b/openapi_schema_pydantic/v3/v3_1_0/discriminator.py
index 699d4ea..124f216 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/discriminator.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/discriminator.py
@@ -2,6 +2,8 @@
 
 from pydantic import BaseModel, Extra
 
+from ._config import DefaultConfig
+
 
 class Discriminator(BaseModel):
     """
@@ -24,8 +26,7 @@ class Discriminator(BaseModel):
     An object to hold mappings between payload values and schema names or references.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {
diff --git a/openapi_schema_pydantic/v3/v3_1_0/encoding.py b/openapi_schema_pydantic/v3/v3_1_0/encoding.py
index 7dc6220..60b7cd3 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/encoding.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/encoding.py
@@ -2,6 +2,7 @@
 
 from pydantic import BaseModel, Extra
 
+from ._config import DefaultConfig
 from .reference import Reference
 
 
@@ -67,8 +68,7 @@ class Encoding(BaseModel):
     then the value of [`contentType`](#encodingContentType) (implicit or explicit) SHALL be ignored.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {
diff --git a/openapi_schema_pydantic/v3/v3_1_0/example.py b/openapi_schema_pydantic/v3/v3_1_0/example.py
index a8c8bce..e909492 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/example.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/example.py
@@ -2,9 +2,10 @@
 
 from pydantic import BaseModel, Extra
 
+from ._config import DefaultConfig
 
-class Example(BaseModel):
 
+class Example(BaseModel):
     summary: Optional[str] = None
     """
     Short description for the example.
@@ -33,8 +34,7 @@ class Example(BaseModel):
     See the rules for resolving [Relative References](#relativeReferencesURI).
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {"summary": "A foo example", "value": {"foo": "bar"}},
diff --git a/openapi_schema_pydantic/v3/v3_1_0/external_documentation.py b/openapi_schema_pydantic/v3/v3_1_0/external_documentation.py
index 0ce2747..8586388 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/external_documentation.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/external_documentation.py
@@ -1,5 +1,6 @@
 from typing import Optional
 
+from ._config import DefaultConfig
 from pydantic import AnyUrl, BaseModel, Extra
 
 
@@ -18,6 +19,5 @@ class ExternalDocumentation(BaseModel):
     Value MUST be in the form of a URL.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {"examples": [{"description": "Find more info here", "url": "https://example.com"}]}
diff --git a/openapi_schema_pydantic/v3/v3_1_0/header.py b/openapi_schema_pydantic/v3/v3_1_0/header.py
index c413cdc..18dca5c 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/header.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/header.py
@@ -1,5 +1,6 @@
 from pydantic import Extra, Field
 
+from ._config import DefaultConfig
 from .parameter import Parameter
 
 
@@ -16,8 +17,7 @@ class Header(Parameter):
     name = Field(default="", const=True)
     param_in = Field(default="header", const=True, alias="in")
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         allow_population_by_field_name = True
         schema_extra = {
             "examples": [
diff --git a/openapi_schema_pydantic/v3/v3_1_0/info.py b/openapi_schema_pydantic/v3/v3_1_0/info.py
index 5e8955b..efd5db7 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/info.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/info.py
@@ -2,6 +2,7 @@
 
 from pydantic import AnyUrl, BaseModel, Extra
 
+from ._config import DefaultConfig
 from .contact import Contact
 from .license import License
 
@@ -51,8 +52,7 @@ class Info(BaseModel):
     (which is distinct from the [OpenAPI Specification version](#oasVersion) or the API implementation version).
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {
diff --git a/openapi_schema_pydantic/v3/v3_1_0/license.py b/openapi_schema_pydantic/v3/v3_1_0/license.py
index f0ba1bb..5c2c4d9 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/license.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/license.py
@@ -1,6 +1,7 @@
 from typing import Optional
 
 from pydantic import AnyUrl, BaseModel, Extra
+from ._config import DefaultConfig
 
 
 class License(BaseModel):
@@ -26,8 +27,7 @@ class License(BaseModel):
     The `url` field is mutually exclusive of the `identifier` field.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {"name": "Apache 2.0", "identifier": "Apache-2.0"},
diff --git a/openapi_schema_pydantic/v3/v3_1_0/link.py b/openapi_schema_pydantic/v3/v3_1_0/link.py
index df82633..2cc659d 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/link.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/link.py
@@ -2,6 +2,7 @@
 
 from pydantic import BaseModel, Extra
 
+from ._config import DefaultConfig
 from .server import Server
 
 
@@ -62,8 +63,7 @@ class Link(BaseModel):
     A server object to be used by the target operation.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {"operationId": "getUserAddressByUUID", "parameters": {"userUuid": "$response.body#/uuid"}},
diff --git a/openapi_schema_pydantic/v3/v3_1_0/media_type.py b/openapi_schema_pydantic/v3/v3_1_0/media_type.py
index 07b3986..9672abe 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/media_type.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/media_type.py
@@ -2,6 +2,7 @@
 
 from pydantic import BaseModel, Extra, Field
 
+from ._config import DefaultConfig
 from .encoding import Encoding
 from .example import Example
 from .reference import Reference
@@ -48,8 +49,7 @@ class MediaType(BaseModel):
     when the media type is `multipart` or `application/x-www-form-urlencoded`.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         allow_population_by_field_name = True
         schema_extra = {
             "examples": [
diff --git a/openapi_schema_pydantic/v3/v3_1_0/oauth_flow.py b/openapi_schema_pydantic/v3/v3_1_0/oauth_flow.py
index 57ded57..4ef8141 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/oauth_flow.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/oauth_flow.py
@@ -2,6 +2,8 @@
 
 from pydantic import AnyUrl, BaseModel, Extra
 
+from ._config import DefaultConfig
+
 
 class OAuthFlow(BaseModel):
     """
@@ -38,8 +40,7 @@ class OAuthFlow(BaseModel):
     The map MAY be empty.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {
diff --git a/openapi_schema_pydantic/v3/v3_1_0/oauth_flows.py b/openapi_schema_pydantic/v3/v3_1_0/oauth_flows.py
index c60a8ff..1113dc8 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/oauth_flows.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/oauth_flows.py
@@ -2,6 +2,7 @@
 
 from pydantic import BaseModel, Extra
 
+from ._config import DefaultConfig
 from .oauth_flow import OAuthFlow
 
 
@@ -34,5 +35,5 @@ class OAuthFlows(BaseModel):
     Previously called `accessCode` in OpenAPI 2.0.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
+        pass
diff --git a/openapi_schema_pydantic/v3/v3_1_0/open_api.py b/openapi_schema_pydantic/v3/v3_1_0/open_api.py
index dc1e534..f0bfe99 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/open_api.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/open_api.py
@@ -2,6 +2,7 @@
 
 from pydantic import BaseModel, Extra
 
+from ._config import DefaultConfig
 from .components import Components
 from .external_documentation import ExternalDocumentation
 from .info import Info
@@ -86,5 +87,5 @@ class OpenAPI(BaseModel):
     Additional external documentation.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
+        pass
diff --git a/openapi_schema_pydantic/v3/v3_1_0/operation.py b/openapi_schema_pydantic/v3/v3_1_0/operation.py
index 7b5cde3..3292987 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/operation.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/operation.py
@@ -2,6 +2,7 @@
 
 from pydantic import BaseModel, Extra
 
+from ._config import DefaultConfig
 from .callback import Callback
 from .external_documentation import ExternalDocumentation
 from .parameter import Parameter
@@ -106,8 +107,7 @@ class Operation(BaseModel):
     it will be overridden by this value.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {
diff --git a/openapi_schema_pydantic/v3/v3_1_0/parameter.py b/openapi_schema_pydantic/v3/v3_1_0/parameter.py
index e4f69c4..b9fac7d 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/parameter.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/parameter.py
@@ -2,6 +2,7 @@
 
 from pydantic import BaseModel, Field, Extra
 
+from ._config import DefaultConfig
 from .example import Example
 from .media_type import MediaType
 from .reference import Reference
@@ -140,8 +141,7 @@ class Parameter(BaseModel):
     The map MUST only contain one entry.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         allow_population_by_field_name = True
         schema_extra = {
             "examples": [
diff --git a/openapi_schema_pydantic/v3/v3_1_0/path_item.py b/openapi_schema_pydantic/v3/v3_1_0/path_item.py
index 5625617..e501a00 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/path_item.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/path_item.py
@@ -2,6 +2,7 @@
 
 from pydantic import BaseModel, Extra, Field
 
+from ._config import DefaultConfig
 from .operation import Operation
 from .parameter import Parameter
 from .reference import Reference
@@ -92,8 +93,7 @@ class PathItem(BaseModel):
     [OpenAPI Object's components/parameters](#componentsParameters).
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         allow_population_by_field_name = True
         schema_extra = {
             "examples": [
diff --git a/openapi_schema_pydantic/v3/v3_1_0/reference.py b/openapi_schema_pydantic/v3/v3_1_0/reference.py
index 76e16c3..77a1bab 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/reference.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/reference.py
@@ -2,6 +2,8 @@
 
 from pydantic import BaseModel, Extra, Field
 
+from ._config import DefaultConfig
+
 
 class Reference(BaseModel):
     """
@@ -29,8 +31,7 @@ class Reference(BaseModel):
     If the referenced object-type does not allow a `description` field, then this field has no effect.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         allow_population_by_field_name = True
         schema_extra = {
             "examples": [{"$ref": "#/components/schemas/Pet"}, {"$ref": "Pet.json"}, {"$ref": "definitions.json#/Pet"}]
diff --git a/openapi_schema_pydantic/v3/v3_1_0/request_body.py b/openapi_schema_pydantic/v3/v3_1_0/request_body.py
index 1bf58ce..464c02a 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/request_body.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/request_body.py
@@ -2,6 +2,7 @@
 
 from pydantic import BaseModel, Extra
 
+from ._config import DefaultConfig
 from .media_type import MediaType
 
 
@@ -30,8 +31,7 @@ class RequestBody(BaseModel):
     Determines if the request body is required in the request. Defaults to `false`.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {
diff --git a/openapi_schema_pydantic/v3/v3_1_0/response.py b/openapi_schema_pydantic/v3/v3_1_0/response.py
index 1f7042c..ee12469 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/response.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/response.py
@@ -2,6 +2,7 @@
 
 from pydantic import BaseModel, Extra
 
+from ._config import DefaultConfig
 from .header import Header
 from .link import Link
 from .media_type import MediaType
@@ -43,8 +44,7 @@ class Response(BaseModel):
     following the naming constraints of the names for [Component Objects](#componentsObject).
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {
diff --git a/openapi_schema_pydantic/v3/v3_1_0/responses.py b/openapi_schema_pydantic/v3/v3_1_0/responses.py
index 569e08b..317fc40 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/responses.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/responses.py
@@ -1,5 +1,6 @@
 from typing import Dict, Union
 
+from ._config import DefaultConfig
 from .response import Response
 from .reference import Reference
 
diff --git a/openapi_schema_pydantic/v3/v3_1_0/schema.py b/openapi_schema_pydantic/v3/v3_1_0/schema.py
index 1739f0e..2b3f0f6 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/schema.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/schema.py
@@ -1,6 +1,8 @@
 from typing import Any, Dict, List, Optional, Union
 
 from pydantic import BaseModel, Extra, Field
+
+from ._config import DefaultConfig
 from .discriminator import Discriminator
 from .external_documentation import ExternalDocumentation
 from .reference import Reference
@@ -830,8 +832,7 @@ class Schema(BaseModel):
     Use of example is discouraged, and later versions of this specification may remove it.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         allow_population_by_field_name = True
         schema_extra = {
             "examples": [
diff --git a/openapi_schema_pydantic/v3/v3_1_0/security_requirement.py b/openapi_schema_pydantic/v3/v3_1_0/security_requirement.py
index 0fb703f..6f77fae 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/security_requirement.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/security_requirement.py
@@ -1,5 +1,6 @@
 from typing import Dict, List
 
+from ._config import DefaultConfig
 
 SecurityRequirement = Dict[str, List[str]]
 """
diff --git a/openapi_schema_pydantic/v3/v3_1_0/security_scheme.py b/openapi_schema_pydantic/v3/v3_1_0/security_scheme.py
index e1761d0..c72208b 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/security_scheme.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/security_scheme.py
@@ -2,6 +2,7 @@
 
 from pydantic import AnyUrl, BaseModel, Extra, Field
 
+from ._config import DefaultConfig
 from .oauth_flows import OAuthFlows
 
 
@@ -71,8 +72,7 @@ class SecurityScheme(BaseModel):
     This MUST be in the form of a URL. The OpenID Connect standard requires the use of TLS.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         allow_population_by_field_name = True
         schema_extra = {
             "examples": [
diff --git a/openapi_schema_pydantic/v3/v3_1_0/server.py b/openapi_schema_pydantic/v3/v3_1_0/server.py
index aeeefd5..d011128 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/server.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/server.py
@@ -2,6 +2,7 @@
 
 from pydantic import BaseModel, Extra
 
+from ._config import DefaultConfig
 from .server_variable import ServerVariable
 
 
@@ -30,8 +31,7 @@ class Server(BaseModel):
     The value is used for substitution in the server's URL template.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {"url": "https://development.gigantic-server.com/v1", "description": "Development server"},
diff --git a/openapi_schema_pydantic/v3/v3_1_0/server_variable.py b/openapi_schema_pydantic/v3/v3_1_0/server_variable.py
index ad3d989..fa72290 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/server_variable.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/server_variable.py
@@ -1,5 +1,6 @@
 from typing import List, Optional
 
+from ._config import DefaultConfig
 from pydantic import BaseModel, Extra
 
 
@@ -27,5 +28,5 @@ class ServerVariable(BaseModel):
     [CommonMark syntax](https://spec.commonmark.org/) MAY be used for rich text representation.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
+        pass
diff --git a/openapi_schema_pydantic/v3/v3_1_0/tag.py b/openapi_schema_pydantic/v3/v3_1_0/tag.py
index 24e926a..ca23efd 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/tag.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/tag.py
@@ -2,6 +2,7 @@
 
 from pydantic import BaseModel, Extra
 
+from ._config import DefaultConfig
 from .external_documentation import ExternalDocumentation
 
 
@@ -27,6 +28,5 @@ class Tag(BaseModel):
     Additional external documentation for this tag.
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {"examples": [{"name": "pet", "description": "Pets operations"}]}
diff --git a/openapi_schema_pydantic/v3/v3_1_0/xml.py b/openapi_schema_pydantic/v3/v3_1_0/xml.py
index c9ae224..f2b1363 100644
--- a/openapi_schema_pydantic/v3/v3_1_0/xml.py
+++ b/openapi_schema_pydantic/v3/v3_1_0/xml.py
@@ -2,6 +2,8 @@
 
 from pydantic import BaseModel, Extra
 
+from ._config import DefaultConfig
+
 
 class XML(BaseModel):
     """
@@ -47,8 +49,7 @@ class XML(BaseModel):
     The definition takes effect only when defined alongside `type` being `array` (outside the `items`).
     """
 
-    class Config:
-        extra = Extra.ignore
+    class Config(DefaultConfig):
         schema_extra = {
             "examples": [
                 {"name": "animal"},
diff --git a/tests/test_global_config.py b/tests/test_global_config.py
new file mode 100644
index 0000000..8e4d967
--- /dev/null
+++ b/tests/test_global_config.py
@@ -0,0 +1,59 @@
+from typing import ContextManager
+import pytest
+from contextlib import nullcontext as does_not_raise
+from pydantic import Extra, ValidationError
+
+from openapi_schema_pydantic import OpenAPI, Operation, PathItem, Info
+from openapi_schema_pydantic.v3.v3_1_0._config import DefaultConfig
+
+
+@pytest.mark.parametrize(
+    "cm,extra",
+    [
+        (pytest.raises(AttributeError), Extra.ignore),
+        (pytest.raises(ValidationError), Extra.forbid),
+        (does_not_raise(), Extra.allow),
+    ],
+)
+def test_dumb_key(
+    monkeypatch: pytest.MonkeyPatch,
+    cm: ContextManager,
+    extra: Extra,
+):
+    with monkeypatch.context() as m:
+        m.setattr(DefaultConfig, "extra", extra)
+        with cm:
+            api = OpenAPI(
+                info=Info(
+                    title="dumb test",
+                    version="3",
+                ),
+                dumb="DUMB",
+            )
+            assert api.dumb == "DUMB"
+
+@pytest.mark.parametrize(
+    "cm,extra",
+    [
+        (pytest.raises(AttributeError), Extra.ignore),
+        (pytest.raises(ValidationError), Extra.forbid),
+        (does_not_raise(), Extra.allow),
+    ],
+)
+def test_dumb_key_manual_assignment_of_config_value(
+    monkeypatch: pytest.MonkeyPatch,
+    cm: ContextManager,
+    extra: Extra,
+):
+    with monkeypatch.context() as m:
+        DefaultConfig.extra = extra
+        #m.setattr(DefaultConfig, "extra", extra)
+        with cm:
+            api = OpenAPI(
+                info=Info(
+                    title="dumb test",
+                    version="3",
+                ),
+                dumb="DUMB",
+            )
+            assert api.dumb == "DUMB"