The code appears to be a simple implementation of a Dependency Injection (DI) container in PHP. Here are some observations and suggestions:

The code uses type hints and return type declarations, and also declares strict types, which is good practice.

The code defines a Container class that implements the ContainerInterface interface, which defines two methods, get() and has(), which are used to retrieve instances of objects from the container and check if they exist in the container, respectively.

The set() method is used to bind a concrete implementation to an interface or abstract class.

The resolve() method is used to create a new instance of a class and its dependencies. It uses reflection to inspect the constructor of the class and its parameters to create the required dependencies.

The code does not implement caching or singleton support, optional parameters, or annotations, as indicated by the TODO comments. These features can be added in future updates.

The code checks for circular references, which is a good thing to do. However, it only checks for direct circular references and does not handle indirect circular references. For example, if ClassA depends on ClassB, and ClassB depends on ClassC, which in turn depends on ClassA, the code would not detect this circular reference. This can be addressed by maintaining a stack of dependencies and checking for cycles in the stack.

The code assumes that all dependencies can be resolved by the container. However, some dependencies may not be registered in the container, in which case the code throws a NotFoundException. A better approach would be to allow dependencies to be resolved by other means, such as through constructor arguments or setters, in addition to using the container.

Overall, the code is a good starting point for a simple DI container. However, it lacks some advanced features and could be improved to handle more complex scenarios.