'If no explicit attribute defined, retrieve value from entity.
Tries to get the value on the object normally, but failing that
retrieves value from contained entity.
Args:
key: Name of attribute.
Raises:
AttributeError when there is no attribute for key on object or
contained entity.'

def __getattr__(self, key):

    _dynamic_properties = self._dynamic_properties
    if ((_dynamic_properties is not None) and (key in _dynamic_properties)):
        return _dynamic_properties[key]
    else:
        return getattr(super(Expando, self), key)
