public function has($value)
    {
        $id = is_object($value) ? spl_object_hash($value) : $value;
        return isset($this->_data[$id]);
    }
public function has($value)
    {
        $id = is_object($value) ? spl_object_hash($value) : $value;
        return isset($this->_data[$id]);
    }
public function has ( $ value ) { $ id = is_object ( $ value ) ? spl_object_hash ( $ value ) : $ value ; return isset ( $ this -> _data [ $ id ] ) ; }
Checks if an object with a specific ID has already been collected.

@param  mixed   $value A value.
@return boolean        Returns `true` if exists, `false` otherwise.
Checks if an object with a specific ID has already been collected .