code: function( name, value, match ) {
  		var self = this,
  			result = munit.isError( value ) ?
  				self._errorMatch( value, match ) :
  				{ passed: false, extra: "Value is not an Error '" + value + "'" };
  
  		return self.ok( name, result.passed, self.isError, result.extra );
  	}
docs: Testing value for Error object