code: function injectData(tokenValue, options, key) {
      var data;
      if (~options.contentType.indexOf('application/json')) {
          data = options.data ? JSON.parse(options.data) : {};
          data[key] = tokenValue;
          options.data = JSON.stringify(data);
      } else {
          options.data += options.data ? '&' : '';
          options.data += key + '=' + tokenValue;
      }
  }
docs: Inject CSRF token via POST body
  
  @param {string} tokenValue CSRF token value
  @param {object} options jQuery prefilter options
  @param {string} key POST data key