code: func (bf *BitField) FromProperty(p datastore.Property) error {
  	bin, ok := p.Value().([]byte)
  	if !ok {
  		return fmt.Errorf("expected %s, got %s", datastore.PTBytes, p.Type())
  	}
  	return bf.UnmarshalBinary(bin)
  }
docs: // FromProperty implements datastore.PropertyConverter