code: function (fileName, outFileName, config) {
              //Read in the file. Make sure we have a JS string.
              var originalFileContents = file.readFile(fileName),
                  fileContents = flattenCss(fileName, originalFileContents, config.cssImportIgnore),
                  startIndex, endIndex;
  
              //Do comment removal.
              try {
                  startIndex = -1;
                  //Get rid of comments.
                  while ((startIndex = fileContents.indexOf("/*")) !== -1) {
                      endIndex = fileContents.indexOf("*/", startIndex + 2);
                      if (endIndex === -1) {
                          throw "Improper comment in CSS file: " + fileName;
                      }
                      fileContents = fileContents.substring(0, startIndex) + fileContents.substring(endIndex + 2, fileContents.length);
                  }
                  //Get rid of newlines.
                  if (config.optimizeCss.indexOf(".keepLines") === -1) {
                      fileContents = fileContents.replace(/[\r\n]/g, "");
                      fileContents = fileContents.replace(/\s+/g, " ");
                      fileContents = fileContents.replace(/\{\s/g, "{");
                      fileContents = fileContents.replace(/\s\}/g, "}");
                  } else {
                      //Remove multiple empty lines.
                      fileContents = fileContents.replace(/(\r\n)+/g, "\r\n");
                      fileContents = fileContents.replace(/(\n)+/g, "\n");
                  }
              } catch (e) {
                  fileContents = originalFileContents;
                  logger.error("Could not optimized CSS file: " + fileName + ", error: " + e);
              }
  
              file.saveUtf8File(outFileName, fileContents);
          }
docs: Optimizes one CSS file, inlining @import calls, stripping comments, and
  optionally removes line returns.
  @param {String} fileName the path to the CSS file to optimize
  @param {String} outFileName the path to save the optimized file.
  @param {Object} config the config object with the optimizeCss and
  cssImportIgnore options.