Entityhub Sesame Model returns Sesame BNodes as Entityhub Reference

The SesameModel for the Entithub converts Sesame BNodes as 'o.a.s.entityhub.sesame.model.RdfBNode' instances. As RdfBNode implements the Entityhub 'Reference' interface Sesame BNodes are in fact represented like URIs.

This can create problems when serializing Entityhub Representations in RDF by as BNodes are serialized as URIs like in the following Example

    <http://example.org/mySkos#Concept123>
        a <http://www.w3.org/2004/02/skos/core#Concept>;
        <http://purl.org/dc/elements/1.1/identifier> "123" ;
        <http://www.w3.org/2004/02/skos/core#prefLabel> "Concept123"@en;
        <http://www.w3.org/2004/02/skos/core#scopeNote> 
            <5d8580be71044a88bcfe9852d1e9cfb6node17c4j452vx19576> , 
            <5d8580be71044a88bcfe9852d1e9cfb6node17c4j452vx19634> .

In this example scopeNode values do use a BNode to represent the nary relation to the Note, the creator of the Note, the date of creation ...

However the BNode is serialized as URI because the Sesame Model reports it as an Reference (a RdfBNode).

To avoid this the Sesame Model should be changed to simple ignore BNodes.