code: function (contents, wfCb) {
          async.eachSeries(contents.split('\n'), function (line, eachCb) {
            setImmediateCompat(function() {
              if (line && line.indexOf('#') !== 0) {
                var directive = line.match(DIRECTIVE_REGEX);
                if (!directive) {
                  eachCb(new Error('Bad directive in manifest file: ' + line));
                } else {
                  var cmd = directive[1];
                  var file = directive[2];
                  if (self[cmd]) {
                    self[cmd](manifest, assetBundle, file, eachCb);
                  } else {
                    eachCb(new Error('Bad directive in manifest file: ' + line));
                  }
                }
              } else {
                eachCb();
              }
            });
          }, wfCb);
        }
docs: For each line, process the directive on that line