public function containsCallback(callable $callback)
	{
		// Normalize the callback
		$pc = new ProgrammableCallback($callback);
		$callback = $pc->getCallback();
		foreach ($this->items as $filter)
		{
			if ($callback === $filter->getCallback())
			{
				return true;
			}
		}

		return false;
	}
public function containsCallback(callable $callback)
	{
		// Normalize the callback
		$pc = new ProgrammableCallback($callback);
		$callback = $pc->getCallback();
		foreach ($this->items as $filter)
		{
			if ($callback === $filter->getCallback())
			{
				return true;
			}
		}

		return false;
	}
public function containsCallback ( callable $ callback ) { // Normalize the callback $ pc = new ProgrammableCallback ( $ callback ) ; $ callback = $ pc -> getCallback ( ) ; foreach ( $ this -> items as $ filter ) { if ( $ callback === $ filter -> getCallback ( ) ) { return true ; } } return false ; }
Test whether this filter chain contains given callback

@param  callable $callback
@return bool
Test whether this filter chain contains given callback