code: @Override
    public void exitNamed_version(VersionParser.Named_versionContext ctx)
    {
      IVersion version = null;
      try {
        version = new NamedVersion(ctx.getText());
      }
      catch (InvalidRangeException e) {
        throw new InvalidRangeRuntimeException(e.getMessage(), e);
      }
      stack.push(version);
    }
docs: Get a named version.