'Load dynamic properties from entity.
Expando needs to do a second pass to add the entity values which were
ignored by Model because they didn\'t have an corresponding predefined
property on the model.
Args:
entity: Entity which contain values to search dyanmic properties for.'

@classmethod
def _load_entity_values(cls, entity):

    entity_values = super(Expando, cls)._load_entity_values(entity)
    for (key, value) in entity.iteritems():
        if (key not in entity_values):
            entity_values[str(key)] = value
    return entity_values
