A trace is a series of spans (often RPC calls) which form a latency tree.
The root span is where trace_id = id and parent_id = Nil. The root span is
usually the longest interval in the trace, starting with a SERVER_RECV
annotation and ending with a SERVER_SEND.
This Proxy trait allows you to extend the Span trait with additional state or
behavior and implement the read-only methods from Span using an underlying
instance.
A trace is a series of spans (often RPC calls) which form a latency tree.
The root span is where trace_id = id and parent_id = Nil. The root span is usually the longest interval in the trace, starting with a SERVER_RECV annotation and ending with a SERVER_SEND.