public function redrawControl($snippet = NULL, $redraw = TRUE)
	{
		if ($redraw) {
			$this->invalidSnippets[$snippet === NULL ? "\0" : $snippet] = TRUE;

		} elseif ($snippet === NULL) {
			$this->invalidSnippets = [];

		} else {
			$this->invalidSnippets[$snippet] = FALSE;
		}
	}