This type represents the minimal information to store in continuation-local
storage for a request. We store either a root span corresponding to the
request, or a sentinel value (UNCORRELATED_SPAN or UNTRACED_SPAN) that tells
us that the request is not being traced (with the exact sentinel value
specifying whether this is on purpose or by accident, respectively).
When we store an actual root span, the only information we need is its
current trace/span fields.
This type represents the minimal information to store in continuation-local storage for a request. We store either a root span corresponding to the request, or a sentinel value (UNCORRELATED_SPAN or UNTRACED_SPAN) that tells us that the request is not being traced (with the exact sentinel value specifying whether this is on purpose or by accident, respectively).
When we store an actual root span, the only information we need is its current trace/span fields.