pakmanaged.js
function AssertionError (message, _props, ssf) {
      var extend = exclude('name', 'message', 'stack', 'constructor', 'toJSON')
        , props = extend(_props || {});
    
      // default values
      this.message = message || 'Unspecified AssertionError';
      this.showDiff = false;
    
      // copy from properties
      for (var key in props) {
        this[key] = props[key];
      }
    
      // capture stack trace
      ssf = ssf || arguments.callee;
      if (ssf && Error.captureStackTrace) {
        Error.captureStackTrace(this, ssf);
      } else {
        this.stack = new Error().stack;
      }
    }
function AssertionError (message, _props, ssf) {
      var extend = exclude('name', 'message', 'stack', 'constructor', 'toJSON')
        , props = extend(_props || {});
    
      // default values
      this.message = message || 'Unspecified AssertionError';
      this.showDiff = false;
    
      // copy from properties
      for (var key in props) {
        this[key] = props[key];
      }
    
      // capture stack trace
      ssf = ssf || arguments.callee;
      if (ssf && Error.captureStackTrace) {
        Error.captureStackTrace(this, ssf);
      } else {
        this.stack = new Error().stack;
      }
    }
### AssertionError

An extension of the JavaScript `Error` constructor for
assertion and validation scenarios.

@param {String} message
@param {Object} properties to include (optional)
@param {callee} start stack function (optional)