Stack Overflow - Wk_of_Angmar's Question

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<script type="text/javascript">
"use strict";
Math.isNumber = function(number) {
    return (number >= 0 || number < 0);
};
//Try using function in console AFTER page loaded in Firefox.
</script>
</head>
<body>
</body>
</html>