Uses super()._take_values() method, but replaces content of
        the cached value to the value assossiated with context's session.

        :param item: GPflow parameter.
        :return: dictionary snapshot of the parameter object.

def _take_values(self, item: Parameter) -> DictBasicType:
        """Uses super()._take_values() method, but replaces content of
        the cached value to the value assossiated with context's session.

        :param item: GPflow parameter.
        :return: dictionary snapshot of the parameter object."""

        session = self.context.session
        values = super()._take_values(item)
        cached_value = np.array(item.read_value(session=session))
        values['_value'] = cached_value
        return values