how to find out if a custom filter handler is in use when in hook_views_query_alter() Drupal 7. I have a custom filter handler which needs to amend the views query. As the filter can be added to any view I can't simply check for view name in the hook_views_query_alter()

I know the filtername exists somewhere in the $views parameter to hook_views_query_alter() within its arrays of array of objects I have yet to find an efficient way of checking if the filter is in use. 

anyone come up with a solution to similar?
Found a way, you can check for the filtername in the view object 
e.g.  if (isset($view->filter['myfiltername'])) {