def METHOD_NAME(self):
    self.prepare_data()
    handle = self.create_route()
    url = '/user'
    # case 1: success
    auth_header = (
        'OAuth oauth_consumer_key="client",'
        'oauth_signature_method="PLAINTEXT",'
        'oauth_token="valid-token",'
        'oauth_signature="secret&valid-token-secret"'
    )
    request = self.factory.get(url, HTTP_AUTHORIZATION=auth_header)
    resp = handle(request)
    data = json.loads(to_unicode(resp.content))
    self.assertIn('username', data)
    # case 2: invalid signature
    auth_header = auth_header.replace('valid-token-secret', 'invalid')
    request = self.factory.get(url, HTTP_AUTHORIZATION=auth_header)
    resp = handle(request)
    data = json.loads(to_unicode(resp.content))
    self.assertEqual(data['error'], 'invalid_signature')