code: public function visitObjectType(ObjectType $type)
      {
          $this->typeCheck->visitObjectType(func_get_args());
  
          if (null === $type->ofType()) {
              $call = new Call(QualifiedIdentifier::fromString('\is_object'));
              $call->add($this->valueExpression());
  
              return $call;
          }
  
          return new InstanceOfType(
              $this->valueExpression(),
              QualifiedIdentifier::fromString($type->ofType()->string())
          );
      }
docs: @param ObjectType $type
  
  @return Call|InstanceOfType