function withActiveSpan(span, callback) {
  return withScope(scope => {
    // eslint-disable-next-line deprecation/deprecation
    scope.setSpan(span);
    return callback(scope);
  });
}
Forks the current scope and sets the provided span as active span in the context of the provided callback.

@param span Spans started in the context of the provided callback will be children of this span.
@param callback Execution context in which the provided span will be active. Is passed the newly forked scope.
@returns the value returned from the provided callback function.