public void setUsage(final String usageText) {
    usage = usageText;
  }
Attaches a usage message to the exception for later consumption.

@param usageText text to display to user to guide them to correct usage. This is generated and
       set by the <code>ArgsProcessor</code>.
extensions/geode-modules-session/src/main/java/org/apache/geode/modules/session/installer/args/UsageException.java