old_contents: module.exports = function (TAPIC, _getJSON) {
    /**
    * Checks if "user" is following "channel". This is an asynchronous function and requires a callback.
    * @param  {string} user     The user id to check.
    * @param  {string} channel  The channel id to check.
    * @param  {function} callback The function that's called when the check is complete. Callback is given an object with isFollowing (boolean) and dateFollowed (string).
    * @function isFollowing
    */
    TAPIC.isFollowing = function (user, channel, callback) {
      // https://api.twitch.tv/kraken/users/skhmt/follows/channels/food
      if (typeof user != 'string' || typeof channel != 'string' || typeof callback != 'function') {
        return console.error('Invalid parameters. Usage: TAPIC.isFollowing(user_id, channel_id, callback);');
      }
      const url = 'https://api.twitch.tv/kraken/users/' + encodeURIComponent(user) + '/follows/channels/' + encodeURIComponent(channel);
      _getJSON(
        url,
        function (res) {
          if (res.error) callback({
            isFollowing: false
          });
          else callback({
            isFollowing: true,
            dateFollowed: (new Date(res.created_at).toLocaleString())
          });
        }
      );
    };
  };
  
new_contents: module.exports = function (TAPIC, _getJSON) {
    /**
    * Checks if "user" is following "channel". This is an asynchronous function and requires a callback.
    * @param  {string} user     The user id to check.
    * @param  {string} channel  The channel id to check.
    * @param  {function} callback The function that's called when the check is complete. Callback is given an object with isFollowing (boolean) and dateFollowed (string).
    * @function isFollowing
    */
    TAPIC.isFollowing = function (user, channel, callback) {
      // https://api.twitch.tv/kraken/users/skhmt/follows/channels/food
      if ((typeof user != 'string' && typeof user != 'number') || 
          (typeof channel != 'string' && typeof channel != 'number) || 
           typeof callback != 'function') {
        return console.error('Invalid parameters. Usage: TAPIC.isFollowing(user_id, channel_id, callback);');
      }
      const url = 'https://api.twitch.tv/kraken/users/' + encodeURIComponent(user) + '/follows/channels/' + encodeURIComponent(channel);
      _getJSON(
        url,
        function (res) {
          if (res.created_at) callback({
            isFollowing: true,
            dateFollowed: (new Date(res.created_at).toLocaleString())
          });
          else callback({
            isFollowing: false
          });
        }
      );
    };
  };
  
subject: Update tapic.fn.isFollowing.js