Analyse following RPM build log snippet. Describe contents accurately, without speculation or suggestions for resolution.            
Your analysis must be as concise as possible, while keeping relevant information intact.
Snippet: 
self = <test.pytest.mocktransport.MockTransport object at 0xffffb2cb4c50>
payload = 'fsread1', channel = 'channel.1'
kwargs = {'binary': 'raw', 'path': '/dev/null'}

    def send_open(self, payload, channel=None, **kwargs):
        if channel is None:
            channel = self.get_id('channel')
>       self.send_json('', command='open', channel=channel, payload=payload, **kwargs)
E       TypeError: MockTransport.send_json() got multiple values for argument 'channel'

test/pytest/mocktransport.py:48: TypeError
`TypeError` was identified for call to `send_json` method.