Method removeFilter

/**
 * Remove a filter, either by resource (handed out from the append or prepend function)
 * or via getting the filter list)
 *
 * @param   resource  $resource  The resource.
 * @param   boolean   $byindex   The index of the filter.
 *
 * @return  boolean   Result of operation
 *
 * @since   1.7.0
 */
public function removeFilter(&$resource, $byindex = false)
{
    // Capture PHP errors
    $php_errormsg = '';
    $track_errors = ini_get('track_errors');
    ini_set('track_errors', true);
    if ($byindex) {
        $res = stream_filter_remove($this->filters[$resource]);
    } else {
        $res = stream_filter_remove($resource);
    }
    if ($res && $php_errormsg) {
        $this->setError($php_errormsg);
    }
    // Restore error tracking to what it was before.
    ini_set('track_errors', $track_errors);
    return $res;
}