code: public void addELResolver(ELResolver resolver)
      {
          // The following concrete methods were added for JSF 1.2.  They supply default 
          // implementations that throw UnsupportedOperationException.  
          // This allows old Application implementations to still work.
          Application application = getMyfacesApplicationInstance();
          if (application != null)
          {
              application.addELResolver(resolver);
              return;
          }
          throw new UnsupportedOperationException();
      }
docs: <p>
  Cause an the argument <code>resolver</code> to be added to the resolver chain as specified in section 5.5.1 of
  the JavaServer Faces Specification.
  </p>
  
  <p>
  It is not possible to remove an <code>ELResolver</code> registered with this method, once it has been registered.
  </p>
  
  <p>
  It is illegal to register an ELResolver after the application has received any requests from the client. If an
  attempt is made to register a listener after that time, an IllegalStateException must be thrown. This restriction
  is in place to allow the JSP container to optimize for the common case where no additional
  <code>ELResolvers</code> are in the chain, aside from the standard ones. It is permissible to add
  <code>ELResolvers</code> before or after initialization to a CompositeELResolver that is already in the chain.
  <p>
  
  <p>
  The default implementation throws <code>UnsupportedOperationException</code> and is provided for the sole purpose
  of not breaking existing applications that extend {@link Application}.
  </p>
  
  @since 1.2