Is there any way to determine when an RPC ends using Go's StreamClientInterceptor?

[ryan...@gmail.com]

I'm working on instrumenting Go's streaming RPCs for OpenTracing. Is there a good way to figure out when an RPC ends on the client-side so that a span can be accurately measured? (I also asked this on StackOverflow: http://stackoverflow.com/q/42988396). 

I've been looking into a returning a decorated ClientStream that closes the span when it detects an error or io.EOF, but this doesn't seem like it would work in all cases if the client-side doesn't call Recv until it returns EOF (for example: http://stackoverflow.com/q/42915337).