<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

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