def shh_post(self, from_=None, to=None, *, topics, payload, priority, ttl):
        """https://github.com/ethereum/wiki/wiki/JSON-RPC#shh_post
        """
        # FIXME: Not working
        obj = {
            'from': from_,
            'to': to,
            'topics': topics,
            'payload': payload,
            'priority': hex(priority),
            'ttl': hex(ttl),
        }
        return float((yield from self.rpc_call('shh_post', [obj])))
https://github.com/ethereum/wiki/wiki/JSON-RPC#shh_post