old_contents: (function(root) {
  
    function isBoolean(v) {
      return typeof v === 'boolean' || v instanceof Boolean;
    }
  
    if (typeof exports !== 'undefined') {
      if (typeof module !== 'undefined' && module.exports) {
        exports = module.exports = isBoolean;
      }
      exports.isBoolean = isBoolean;
    } else if (typeof define === 'function' && define.amd) {
      define([], function() {
        return isBoolean;
      });
    } else {
      root.isBoolean = isBoolean;
    }
  
  })(this);
  
  
new_contents: (function(root) {
  
    function isBoolean(v) {
      return Object.prototype.toString.call(v) === '[object Boolean]';
    }
  
    if (typeof exports !== 'undefined') {
      if (typeof module !== 'undefined' && module.exports) {
        exports = module.exports = isBoolean;
      }
      exports.isBoolean = isBoolean;
    } else if (typeof define === 'function' && define.amd) {
      define([], function() {
        return isBoolean;
      });
    } else {
      root.isBoolean = isBoolean;
    }
  
  })(this);
  
  
subject: change check to use toString