How to default to 'this' rather than 'self' when autocompleting method names without 'this' or 'self'?

When I type a method name without '$this->' or 'self::' suffix and press tab, it auto generates the required suffix but it defaults to 'self' if available but I want to change it to '$this' by default.

I.E:

// In Laravel tests

assertNull // press 'tab' for auto completion

self::assertNull(); //generated code

$this->assertNull(); // wanted code

Can't find the settings if exists. Any help would be appreciated. Thanks