jaeger-client -> opentelemetry

vendor/open-telemetry/api/Metrics/ObservableCounterInterface.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\API\Metrics;
+
+interface ObservableCounterInterface
+{
+
+    /**
+     * @param callable(ObserverInterface): void $callback function responsible for
+     *        reporting the measurements (as absolute values)
+     * @return ObservableCallbackInterface token to detach callback
+     */
+    public function observe(callable $callback): ObservableCallbackInterface;
+}