public ProcessStreamReader join(final long millis) throws InterruptedException {
    Thread thread;
    synchronized (this) {
      thread = this.thread;
    }
    if (thread != null) {
      thread.join(millis);
    }
    return this;
  }
Reads the output stream of a Process.

@since GemFire 7.0
geode-core/src/main/java/org/apache/geode/internal/process/ProcessStreamReader.java