docs: def _join_disease(query, disease_definition, disease_id, disease_name):
          """helper function to add a query join to Disease model
          
          :param sqlalchemy.orm.query.Query query: SQL Alchemy query
          :param disease_definition: 
          :param str disease_id: see :attr:`models.Disease.disease_id`
          :param disease_name: 
          :rtype: sqlalchemy.orm.query.Query
          """
          if disease_definition or disease_id or disease_name:
              query = query.join(models.Disease)
  
              if disease_definition:
                  query = query.filter(models.Disease.definition.like(disease_definition))
  
              if disease_id:
                  query = query.filter(models.Disease.disease_id == disease_id)
  
              if disease_name:
                  query = query.filter(models.Disease.disease_name.like(disease_name))
  
          return query