public static function hasFilter($hook = '', callable $callback = null, $priority = null)
    {
        return static::hasHook('filter', $hook, $callback, $priority);
    }
public static function hasFilter($hook = '', callable $callback = null, $priority = null)
    {
        return static::hasHook('filter', $hook, $callback, $priority);
    }
public static function hasFilter ( $ hook = '' , callable $ callback = null , $ priority = null ) { return static :: hasHook ( 'filter' , $ hook , $ callback , $ priority ) ; }
Check if an filter hook is added. Optionally check a specific callback and and priority.

@param  string   $hook     Hook to check
@param  callable $callback Callback to check
@param  int      $priority Priority to check
@return boolean
Check if an filter hook is added . Optionally check a specific callback and and priority .