Decoupling statements about a class in hydra from the original class

Hi,

in Hydra we say that a SupportedOperation expects a type, and we make 
statements about that expected type, e.g. by saying which properties are 
supported.

Since sometimes the expected type might be a type from a third-party 
vocab, we want to make it clear that the statements about the type apply 
only within the current API.

I want to be sure I understand how we decouple our statements about an 
expected class from the original class.

Within a sample response [1] I have found the following idiom. The 
expected class appears to be an rdfs:subClassOf schema:Rating:

"method": "POST",
     "expects": {
       "@type": "Class",
       "subclassOf": "Rating",
       "supportedProperty": [
         {
           "@type": "SupportedProperty",
           "property": "ratingValue",
           "required": true
         },
         {
           "@type": "SupportedProperty",
           "property": "reviewBody",
           "required": false
         }
     }

Is the subclass necessary here for decoupling or could I use 
"@type":"schema:Rating" like below, without inadvertently making 
statements about every schema.org Rating class or causing other problems?

     "expects": {
       "@type": "Rating",
       "supportedProperty": [
         {
           "@type": "SupportedProperty",
           "property": "ratingValue",
           "required": true
         },
         {
           "@type": "SupportedProperty",
           "property": "reviewBody",
           "required": false
         }
     }

To me it seems I am safe, after all the subject of :supportedProperty is 
not identified (has no @id, i.e. it is a blank node), I merely say it is 
an rdf:type schema:Rating and I say that the blank node has two 
supported properties

(putting aside the fact that schema:reviewBody normally "belongs" on a 
schema:Review, not a :Rating and we have not decided yet how to express 
this kind of nesting, see #37 and #26).

Best regards,
Dietrich


[1] http://www.hydra-cg.com/spec/latest/schema.org/