michael@0: load(libdir + "asserts.js");
michael@0: var calledToString = false;
michael@0: assertThrowsInstanceOf(function () { Object.prototype.hasOwnProperty.call(null,
michael@0:                       {toString: function () { calledToString = true; }}); },
michael@0:                        TypeError);
michael@0: assertEq(calledToString, true);