Equivalent to Netty's AttributeMap functionality?

What is, if any, the equivalent to Channel.attr()? I can think of quite a few ways to mimic the feature but it seems like a feature that is quite extensively used in Netty. Considering this I figured there might already be some equivalent method or pattern that solves the problem of attaching data to channel/pipelines/handlers.

Currently there is no equivalent. We’d definitely be open to adding such a thing, though: feel free to open a feature request!