SystemInfo { public static int pid() { if (Pid.PID <= 0) { throw new IllegalStateException("Failed to retrieve the current PID."); } return Pid.PID; } private  SystemInfo(); static int javaVersion(); static String hostname(); static boolean jettyAlpnOptionalOrAvailable(); static int pid(); @Nullable static Inet4Address defaultNonLoopbackIpV4Address(); static long currentTimeMicros(); static OsType osType(); static boolean isLinux();  }
@Test public void pid() { assertThat(SystemInfo.pid()).isPositive(); }