'Ensure client is authorized to use the response_type requested.
:param client_id: Unicode client identifier
:param response_type: Unicode response type, i.e. code, token.
:param client: Client object set by you, see authenticate_client.
:param request: The HTTP Request (oauthlib.common.Request)
:rtype: True or False
Method is used by:
- Authorization Code Grant
- Implicit Grant'

def validate_response_type(self, client_id, response_type, client, request, *args, **kwargs):

    raise NotImplementedError(u'Subclasses    must    implement    this    method.')
