docs: protected NamedSelector namedSelector( String nameWithOptionalAlias ) {
          String[] parts = nameWithOptionalAlias.split("\\s(AS|as)\\s");
          if (parts.length == 2) {
              return new NamedSelector(selector(parts[0]), selector(parts[1]));
          }
          return new NamedSelector(selector(parts[0]));
      }