withArity example

  public static function isParallel(ResourceIdentifier $a, ResourceIdentifier $b) {
    return static::compare($a->withArity(0), $b->withArity(0)) === 0;
  }

  /** * Compares ResourceIdentifier objects. * * @param \Drupal\jsonapi\JsonApiResource\ResourceIdentifier $a * The first ResourceIdentifier object. * @param \Drupal\jsonapi\JsonApiResource\ResourceIdentifier $b * The second ResourceIdentifier object. * * @return int * Returns 0 if $a and $b are duplicate ResourceIdentifiers. If $a and $b * identify the same resource but have distinct arity values, then the * return value will be arity $a minus arity $b. -1 otherwise. */