Adds an inbound processor object to the $inboundProcessors property.
\Drupal\Core\PathProcessor\InboundPathProcessorInterface $processor: The processor object to add.
int $priority: The priority of the processor being added.
public function addInbound(InboundPathProcessorInterface $processor, $priority = 0) {
$this->inboundProcessors[$priority][] = $processor;
$this->sortedInbound = array();
}