code: function (startDir, config) {
              if (config.optimizeCss.indexOf("standard") !== -1) {
                  var i, fileName,
                      fileList = file.getFilteredFileList(startDir, /\.css$/, true);
                  if (fileList) {
                      for (i = 0; i < fileList.length; i++) {
                          fileName = fileList[i];
                          logger.trace("Optimizing (" + config.optimizeCss + ") CSS file: " + fileName);
                          optimize.cssFile(fileName, fileName, config);
                      }
                  }
              }
          }
docs: Optimizes CSS files, inlining @import calls, stripping comments, and
  optionally removes line returns.
  @param {String} startDir the path to the top level directory
  @param {Object} config the config object with the optimizeCss and
  cssImportIgnore options.