the attempts field is an unsigned 16-bit integer
the attempts field is an unsigned 16-bit integer

unpack reference: https://ruby-doc.org/core-2.4.0/String.html#method-i-unpack
nsq mesage format: https://github.com/nsqio/nsq/blob/cc29d7202e35b6d94d361fa9890077048a1d0763/nsqd/message.go#L68-L77

wistia/nsq-ruby