Ambient_span_provider.Callbackstype 'st t = {with_current_span_set_to : 'a. 'st ->
Trace_core__.Types.span ->
(Trace_core__.Types.span -> 'a) ->
'a;with_current_span_set_to span f sets the span as current span, enters f span, and restores the previous current span if any
get_current_span : 'st -> Trace_core__.Types.span option;Access the current span from some ambient scope. This is only supported for collectors that provide a current_span_wrap field.
}