Get last name from sublime snippets variable

Galera,
What is the parameter that has to create a snippet in the sublime, to get the name of the last variable in the script? Example:

$cha = 'erva doce';
dbg <<<<---- Quando eu der tab nisso, queria: 

echo '<pre>';
print_r($cha);
echo '</pre>';
exit;

The snippet already exists, but I did not find anything related to picking the last variable. I believe that having docblokr does something similar.