I think we’re talking past each other.

I was not talking about file descriptors; rather I was talking about the fact that it’s common for Go libraries to do interesting and useful things when you call the `Close()` method on a type. `Close()` is idiomatic go for resource cleanup.

You might wait until close to populate a length and or checksum field in a message header. Or close could submit a buffer of log events to a remote aggregation endpoint.

I’m not saying I agree with APIs that are designed that way, but it’s common enough that you should assume the error return value is significant unless you know otherwise (for Go)