'Bind the `Parameter` to a specific `Model` instance; don\'t use this
directly on *unbound* parameters, i.e. `Parameter` descriptors that
are defined in class bodies.'

def _bind(self, model):

    self._model = model
    self._getter = self._create_value_wrapper(self._getter, model)
    self._setter = self._create_value_wrapper(self._setter, model)
