Error indicates the operation contains an error.

Ok indicates operation has been validated by an Application developers or Operator to have completed successfully, or contain no error.

Unset is the default status code.

SpanOptions describes the options for starting a span.

Span is an interface that accepts attributes and can be distinguished as noop.

SpanFromContext retrieves the existing span from a context.

SpanKind represents the span kind, either Client, Server, Producer, Consumer or undertermine.

StartSpan creates a span and injects into a context, returning a span ender function.