Implements \Drupal\Core\Path\AliasManagerInterface::cacheClear().
public function cacheClear($source = NULL) {
$this->lookupMap = array();
$this->noSource = array();
$this->no_aliases = array();
$this->firstCall = TRUE;
$this->preloadedPathLookups = array();
$this
->pathAliasWhitelistRebuild($source);
}