Please note that main.inc.php, which should be called by index.php, does
the following:

unset($_REQUEST);
unset($_GET);
unset($_POST);

So, you must use \tts\safer_io::sanitize(....); to get those input vars!!!
That method, returns an array of fields, html, and errors, I'll break that down:
    fields are the raw or result of the filter_input function, 
    html is passed an function to escape or sanitize the HTML output in someway (so use it for any output on views),
    errors will have an count > 0 if validation rules were not meet.

Alternatively; use the built in PHP filter_input function.

Likewise, if not using sanitize... then for all HTML output use 
    \tts\safer_io::h(...) to escape it.