def __init__(self, display_name, source, url, reference_id, url_type, date_created, created_by):
Url.__init__(self, 'REFERENCE', display_name, source, url, None, date_created, created_by)
self.reference_id = reference_id
self.url_type = url_type
def __init__(self, display_name, source, url, category, bioentity_id, date_created, created_by):
Url.__init__(self, 'BIOENTITY', display_name, source, url, category, date_created, created_by)
self.bioentity_id = bioentity_id
