Subschema examples

I'd like to use the new subschema feature, but can't seem to get it to work.

Adding the attribute to the sub model like so:
```
fieldWithPath("recipes[]").optional().attributes(schema("RecipeData"))
.description("List of recipes."),
```
generates a resource.json:
```
...
{
"attributes" : {
"schemaName" : "RecipeData"
},
"description" : "List of recipes.",
"ignored" : false,
"path" : "data.recipes[]",
"type" : "ARRAY",
"optional" : true
},
...
```

But openapi.json doesn't seem to get affected at all.
How to use the newly released feature?