code: function _setLanguageForMode(mode, language) {
          if (_modeToLanguageMap[mode]) {
              console.warn("CodeMirror mode \"" + mode + "\" is already used by language " + _modeToLanguageMap[mode]._name + " - cannot fully register language " + language._name +
                           " using the same mode. Some features will treat all content with this mode as language " + _modeToLanguageMap[mode]._name);
              return;
          }
  
          _modeToLanguageMap[mode] = language;
      }
docs: Adds a global mode-to-language association.
  @param {!string} mode The mode to associate the language with
  @param {!Language} language The language to associate with the mode