Encoder.Decode() doesn't seem to be passing along the nats-headers of the message - just the subject and the data

[dsidirop]

I want to support multiple compression algorithms side-by-side for various nats-messages landing on a specific nats-connection and in this context I experimented with creating an all-in-one multi-decoder which relies on nats-headers to figure out the kind of compression (zlib, snappy, brotli etc) that has been employed in the given data-payload of each message. This is similar to what http is doing with http-headers and compression.

However the signature of Encoder.Decode() method doesn't pass nats-headers at all:

Decode(subject string, data []byte, vPtr interface{}) error

I believe this should be:

Decode(subject string, **header Header**, data []byte, vPtr interface{}) error

PS: I'm aware of the fact that one can work around the lack of 'nats-headers' by resorting to hacks of various kinds like relying on specific subject prefixes (snappy.foo.bar, zlib.foo.bar, ...) but I wan't to avoid this sort of thing for obvious reasons.