code: function (username) {
          var channels = null;
          // get the user's object
          this.notifications.some(function (element) {
              if (element.username === username) {
                  channels = element.channels;
                  return true;
              }
              return false;
          });
          return channels;
      }
docs: Returns a list of channels the user is notifying for or null if not found
  
  @param {string} username
  @returns {string[]|null}