   It is only safe to call this method if there are no current resource consumers and if this method has not
     yet been called. Typically this occurs at one of two times:
     <ul>
         <li>During a resource load when the resource is transformed or transcoded before any consumer have
         ever had access to this resource</li>
         <li>After all consumers have released this resource and it has been evicted from the cache</li>
     </ul>

     For most users of this class, the only time this me