'Perform a request, including a proper diff output'

def request_diff(self, path, payload=None):

    self.result['diff'] = dict()
    self.result['diff']['before'] = self.query(path)
    self.request(path, payload=payload)
    self.result['diff']['after'] = self.query(path)
    if (self.result['diff']['before'] != self.result['diff']['after']):
        self.result['changed'] = True
