@Override
  public PidUnavailableException getCause() {
    return (PidUnavailableException) super.getCause();
  }
Returns the cause of this exception.

@return the {@code PidUnavailableException} which is the cause of this exception.
geode-core/src/main/java/org/apache/geode/internal/process/UncheckedPidUnavailableException.java