docs: function copyFileSync(sourceFile, destFile) {
      var BUF_LENGTH, buff, bytesRead, fdr, fdw, pos;
      BUF_LENGTH = 64 * 1024;
      buff = new Buffer(BUF_LENGTH);
      fdr = fs.openSync(sourceFile, "r");
      fdw = fs.openSync(destFile, "w");
      bytesRead = 1;
      pos = 0;
      while (bytesRead > 0) {
      bytesRead = fs.readSync(fdr, buff, 0, BUF_LENGTH, pos);
      fs.writeSync(fdw, buff, 0, bytesRead);
          pos += bytesRead;
      }
      fs.closeSync(fdr);
      return fs.closeSync(fdw)
  }