code: function legacyExtensionLoading (ext, name) {
      if (typeof ext === 'function') {
        ext = ext(new showdown.Converter());
      }
      if (!showdown.helper.isArray(ext)) {
        ext = [ext];
      }
      var valid = validate(ext, name);
  
      if (!valid.valid) {
        throw Error(valid.error);
      }
  
      for (var i = 0; i < ext.length; ++i) {
        switch (ext[i].type) {
          case 'lang':
            langExtensions.push(ext[i]);
            break;
          case 'output':
            outputModifiers.push(ext[i]);
            break;
          default:// should never reach here
            throw Error('Extension loader error: Type unrecognized!!!');
        }
      }
    }
docs: LEGACY_SUPPORT
  @param {*} ext
  @param {string} name