add docs - #35

==== Message #1 ====
User:
So, I can not override the toString method in an interface?

kotlin.Unit

==== Message #2 ====
Assistant:
No, you cannot override the toString() method in an interface in the traditional sense, but there are some nuances to understand:

Why you can't override toString() in an interface:

1. Interfaces don't have implementations: Traditional interfaces only declare method signatures, they don't provide implementations (except for default methods in Java 8+).

2. toString() is inherited from Object: Every class in Java implicitly extends Object, which already provides a toString() implementation.

3. You can't override what you don't inherit: Interfaces don't extend Object, so they don't inherit toString() to override.

What you CAN do:

1. Declare toString() in an interface (but it's redundant):

public interface MyInterface {
    String toString(); // This is allowed but redundant
}

This is legal but unnecessary since every implementing class already has toString() from Object.

2. Provide a default implementation (Java 8+):

public interface MyInterface {
    default String toString() {
        return "MyInterface implementation";
    }
}

However, this won't actually override Object.toString() because the class's inherited toString() takes precedence.

3. The correct approach - Override in implementing classes:

public interface Printable {
    // Interface methods
    void print();
}

public class Document implements Printable {
    private String title;
    
    @Override
    public String toString() {  // This properly overrides Object.toString()
        return "Document: " + title;
    }
    
    @Override
    public void print() {
        System.out.println(toString());
    }
}

Best Practice:

If you want all implementations of your interface to have meaningful toString() representations, document this expectation in the interface's Javadoc rather than trying to enforce it through the interface itself.

/**
 * Implementations should override toString() to provide 
 * a meaningful string representation.
 */
public interface MyInterface {
    // interface methods
}

kotlin.Unit