code: static ModelNode filterSpecToFilter(final String value) {
          final ModelNode filter = new ModelNode(CommonAttributes.FILTER.getName()).setEmptyObject();
          final Iterator<String> iterator = tokens(value).iterator();
          parseFilterExpression(iterator, filter, true);
          return filter;
      }
docs: Converts a {@link CommonAttributes#FILTER_SPEC filter spec} to a legacy {@link CommonAttributes#FILTER filter}.
  
  @param value the value to convert
  
  @return the complex filter object