ObservableGaugeInterface.php

<?php

declare (strict_types=1);
namespace OpenTelemetry\API\Metrics;

interface ObservableGaugeInterface extends AsynchronousInstrument {
    
    /**
     * @param callable(ObserverInterface): void $callback function responsible for
     *        reporting the measurements
     * @return ObservableCallbackInterface token to detach callback
     */
    public function observe(callable $callback) : ObservableCallbackInterface;

}