):
    return {"p": p}


class HeaderModelOptionalListValidationAlias(BaseModel):
    p: list[str] | None = Field(None, validation_alias="p_val_alias")


@app.get("/model-optional-list-validation-alias")
def read_model_optional_list_validation_alias(
    p: Annotated[HeaderModelOptionalListValidationAlias, Header()],
):
    return {"p": p.p}


@pytest.mark.parametrize(