# Buggy code
def node_metadata_exchange():
    # If these nodes already have the same fleet state, no exchange is necessary.
    learner_fleet_state = request.args.get("fleet")
    if learner_fleet_state == this_node.known_nodes.checksum:
        log.debug(
            "Learner already knew fleet state {}; doing nothing.".format(
                learner_fleet_state
            )
        )
        headers = {"Content-Type": "application/octet-stream"}
        payload = this_node.known_nodes.snapshot() + bytes(FLEET_STATES_MATCH)
        signature = this_node.stamp(payload)
        return Response(bytes(signature) + payload, headers=headers)

    sprouts = _node_class.batch_from_bytes(request.data)

    for node in sprouts:
        this_node.remember_node(node)

    # TODO: What's the right status code here?  202?  Different if we already knew about the node(s)?
    return all_known_nodes()


# Traceback (AttributeError)
Traceback (most recent call last):
File "/home/tux/code/nucypher-prod/venv/bin/nucypher", line 33, in <module>
sys.exit(load_entry_point('nucypher', 'console_scripts', 'nucypher')())
File "/home/tux/code/nucypher-prod/venv/lib/python3.8/site-packages/click/core.py", line 829, in __call__
return self.main(*args, **kwargs)
File "/home/tux/code/nucypher-prod/venv/lib/python3.8/site-packages/click/core.py", line 782, in main
rv = self.invoke(ctx)
File "/home/tux/code/nucypher-prod/venv/lib/python3.8/site-packages/click/core.py", line 1259, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/home/tux/code/nucypher-prod/venv/lib/python3.8/site-packages/click/core.py", line 1259, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/home/tux/code/nucypher-prod/venv/lib/python3.8/site-packages/click/core.py", line 1066, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/home/tux/code/nucypher-prod/venv/lib/python3.8/site-packages/click/core.py", line 610, in invoke
return callback(*args, **kwargs)
File "/home/tux/code/nucypher-prod/nucypher/cli/options.py", line 163, in wrapper
return func(**kwargs)
File "/home/tux/code/nucypher-prod/nucypher/cli/options.py", line 163, in wrapper
return func(**kwargs)
File "/home/tux/code/nucypher-prod/nucypher/cli/options.py", line 163, in wrapper
return func(**kwargs)
[Previous line repeated 1 more time]
File "/home/tux/code/nucypher-prod/nucypher/cli/commands/stake.py", line 1263, in set_min_rate
paint_min_rate(emitter, STAKEHOLDER.registry, STAKEHOLDER.policy_agent, staking_address)
File "/home/tux/code/nucypher-prod/nucypher/cli/painting/staking.py", line 229, in paint_min_rate
minimum = policy_agent.min_fee_rate(staker_address)
AttributeError: 'PolicyManagerAgent' object has no attribute 'min_fee_rate'

# Fixed code
def node_metadata_exchange():
    # If these nodes already have the same fleet state, no exchange is necessary.
    learner_fleet_state = request.args.get("fleet")
    if learner_fleet_state == this_node.known_nodes.checksum:
        # log.debug("Learner already knew fleet state {}; doing nothing.".format(learner_fleet_state))  # 1712
        headers = {"Content-Type": "application/octet-stream"}
        payload = this_node.known_nodes.snapshot() + bytes(FLEET_STATES_MATCH)
        signature = this_node.stamp(payload)
        return Response(bytes(signature) + payload, headers=headers)

    sprouts = _node_class.batch_from_bytes(request.data)

    for node in sprouts:
        this_node.remember_node(node)

    # TODO: What's the right status code here?  202?  Different if we already knew about the node(s)?
    return all_known_nodes()