NAMED_THING = 'biolink:NamedThing'

SUBJECT_ID = 'subject'
OBJECT_ID = 'object'
PREDICATE = 'predicate'
NODE_TYPES = 'category'
SYNONYMS = 'equivalent_identifiers'

PRIMARY_KNOWLEDGE_SOURCE = 'biolink:primary_knowledge_source'
AGGREGATOR_KNOWLEDGE_SOURCES = 'biolink:aggregator_knowledge_source'
PUBLICATIONS = 'publications'
XREFS = 'xref'
