code: public Object convertToType(ELContext context, Object obj, Class<?> type) {
          context.setPropertyResolved(false);
          return null;
      }
docs: Converts the given object to the given type. This default implementation
  always returns <code>null</code>.
  
  @param context The EL context for this evaluation
  @param obj     The object to convert
  @param type    The type to which the object should be converted
  
  @return Always <code>null</code>
  
  @since EL 3.0