override em_ticket_get_available_spaces filter

<?php

function my_em_ticket_available_space( $available_spaces, $EM_Ticket ){
	$event_available_spaces  = $EM_Ticket->get_event()->get_bookings()->get_available_spaces();
	return $event_available_spaces;
}
add_filter('em_ticket_get_available_spaces', 'my_em_ticket_available_space', 100, 2);