code: function condenseify(file, options) {
    if (/\.json$/.test(file)) return through();
  
    var appendNewLine = true
      , regex = /^[ \t]+$/
      , isBlank = false
      , eol ='\n';
  
    options = options || {};
  
    function transform(line, encoding, next) {
      if (!line.length) {
        isBlank = true;
        return next();
      }
  
      line = line.toString();
      if (!options['keep-non-empty'] && regex.test(line)) return next();
  
      if (isBlank) {
        isBlank = false;
        this.push(eol);
      }
      appendNewLine = false;
      this.push(line + eol);
      next();
    }
  
    function flush(done) {
      if (appendNewLine) this.push(eol);
      done();
    }
  
    return pumpify(split(), through(transform, flush));
  }
docs: Browserify transform to condense multiple blank lines
  into a single blank line.
  
  @param {String} file File name
  @param {Object} [options] Options object
  @returns {Stream} Transform stream
  @api public