public Throwable getRootCause() {
    if (getCause() == null) {
      return null;
    }
    Throwable root = getCause();
    while (root.getCause() != null) {
      root = root.getCause();
    }
    return root;
  }
Returns the root cause of this <code>GemFireException</code> or <code>null</code> if the cause
is nonexistent or unknown.

@return the root cause of this <code>GemFireException</code>
geode-old-client-support/src/main/java/com/gemstone/gemfire/GemFireException.java