protected void debug(final Throwable t) {
    if (isDebugging()) {
      t.printStackTrace(System.err);
    }
  }
Prints the stack trace of the given Throwable to standard err if debugging has been enabled.

@param t the Throwable who's stack trace is printed to standard err.
@see java.lang.System#err
@see #isDebugging()
@see #debug(String, Object...)
geode-core/src/main/java/org/apache/geode/distributed/AbstractLauncher.java