docs: protected Object columnValue(Object value) {
          switch (type) {
              case PATH:
              case NAME:
              case STRING:
              case REFERENCE:
              case SIMPLEREFERENCE:
              case WEAKREFERENCE:
              case URI:
                  return valueFactories.getStringFactory().create(value);
              case DATE :
                  return ((DateTime) value).getMilliseconds();
              default :
                  return value;
          }
      }