code: function esmangleify(opt) {
  
    // options is mostly the escodegen format
    var format = {
      renumber   : true,
      hexadecimal: true,
      escapeless : true,
      compact    : true,
      semicolons : false,
      parentheses: false
    }
  
    // fail silently allows us to process json (and other non js) files that make it through the transform process
    //  alternatively you could implement a options.filter
    var options = merge(format, {
      failSilently: true
    }, opt);
  
    // transform
    return esprimaTools.createTransform(updater, options);
  }
docs: Esprima based minifier transform for Browserify.
  Options are per the {@link https://github.com/estools/escodegen/wiki/API|escodegen} format.
  @param {object} opt An options hash