code: function ttf2eotTransform() {
    // Return a callback function handling the buffered content
    return function ttf2eotTransformCb(err, buf, cb) {
  
      // Handle any error
      if(err) {
        return cb(new PluginError(PLUGIN_NAME, err, { showStack: true }));
      }
  
      // Use the buffered content
      try {
        buf = new Buffer(ttf2eot(new Uint8Array(buf)).buffer);
        return cb(null, buf);
      } catch(err2) {
        return cb(new PluginError(PLUGIN_NAME, err2, { showStack: true }));
      }
  
    };
  }
docs: File level transform function