Expects a list of dictionaries with ``k`` and ``v`` set to the
            keys and values that will be unwrapped into the output python
            dictionary should have.  Validates the input and then constructs the
            dictionary from the list.

def unwrap(self, value, session=None):
        ''' Expects a list of dictionaries with ``k`` and ``v`` set to the
            keys and values that will be unwrapped into the output python
            dictionary should have.  Validates the input and then constructs the
            dictionary from the list.
        '''
        self.validate_unwrap(value)
        ret = {}
        for value_dict in value:
            k = value_dict['k']
            v = value_dict['v']
            ret[self.key_type.unwrap(k, session=session)] = self.value_type.unwrap(v, session=session)
        return ret