Java 9의 Process API 개선 사항은 무엇입니까?

public class ProcessTest {
   public static void main(String args[]) {
      <strong>ProcessHandle </strong>currentProcess = ProcessHandle.current();
      System.out.println("PID: " + currentProcess.<strong>pid()</strong>);
      <strong>ProcessHandle.Info</strong> currentProcessInfo = currentProcess.<strong>info()</strong>;
      System.out.println("totalCpuDuration: " + currentProcessInfo.<strong>totalCpuDuration()</strong>);
      System.out.println("user: " + currentProcessInfo.<strong>user()</strong>);
   }
}

<strong>PID: 6004
totalCpuDuration: Optional[PT0.421875S]
user: Optional[Tutorialspoint\User]</strong>