Used to hold the biolink class/category of an association. This is a denormalized field used primarily in the SQL serialization of a knowledge graph via KGX.
Association -> 0..1 OntologyClass
| Examples: | Example(value=’biolink:Gene’, description=”The subject category of the association between the gene ‘BRCA1’ and the disease ‘breast cancer’ is ‘biolink:Gene’.”, object=None) |