code: function filter(location) {
      var file = path.basename(location)
        , vim = file.charAt(file.length - 1) === '~'
        , extension = path.extname(location).slice(1);
  
      // filter out the duplicates
      if (~changes.indexOf(location) || vim) return;
  
      changes.push(location);
      process.nextTick(limited);
    }
docs: Filter out the bad files and try to remove some noise. For example vim
  generates some silly swap files in directories or other silly thumb files
  
  The this context of this file will be set the current directory that we are
  watching.
  
  @param {String} file
  @api private