'Subclasses can override this to add custom entity conversion code.
This is called for each entity, after its properties are populated
from the input but before it is stored. Subclasses can override
this to add custom entity handling code.
The entity to be inserted should be returned. If multiple entities
should be inserted, return a list of entities. If no entities
should be inserted, return None or [].
Args:
entity: db.Model
Returns:
db.Model or list of db.Model'

def handle_entity(self, entity):

    return entity
