public static long currentTimeMicros() {
        return JavaVersionSpecific.get().currentTimeMicros();
    }
Returns the number of microseconds since the epoch (00:00:00, 01-Jan-1970, GMT). The precision of the
returned value may vary depending on {@linkplain #javaVersion() Java version}. Currently, Java 9 or
above is required for microsecond precision. {@code System.currentTimeMillis() * 1000} is returned on
Java 8.
core/src/main/java/com/linecorp/armeria/common/util/SystemInfo.java