code: public String toQueryString(Criteria criteria, CriteriaQueryBuilder queryBuilder) {
      StringBuilder builder = new StringBuilder();
      builder.append( queryBuilder.createPositionalParameter() );
      if( negate ) {
        builder.append(" NOT");
      }
      builder.append( " MEMBER OF " );
      builder.append( queryBuilder.getAbsolutePath(criteria, relativePath) );
      return builder.toString();
    }
docs: /*
  @see org.criteria4jpa.criterion.Criterion#toQueryString(org.criteria4jpa.Criteria, org.criteria4jpa.impl.CriteriaQueryBuilder)