public void finish() {
            long endNanos = System.nanoTime();
            duration = (double) (endNanos - startNanos) / 1.0E9D;
            metrics.observe(duration);
        }
Observe an execution, get a duration in second.

@param value duration in second.
oap-server/server-telemetry/telemetry-api/src/main/java/org/apache/skywalking/oap/server/telemetry/api/HistogramMetrics.java