Tracer::inSpan(['name' => 'some process', function () {
    Tracer::addAnnotation('starting request');
    // do something
    Tracer::addAnnotation('in between');
    Tracer::addLink('traceId', 'spanId');
    // do something else
    Tracer::addAnnotation('finished');
});

$span = Tracer::startSpan(['name' => 'some process']);
$scope = Tracer::withSpan($span);

$span->addAnnotation(new Annotation('starting request');
$span->addAnnotation(new Annotation('in between');
$span->addLink(new Link('traceId', 'spanId'));
$span->addAnnotation(new Annotation('finished');

$scope->close();