feat(generic-interface): add wildcard support in generic interface methods

WHAT:
- Introduced `WildcardExample` class with `printContainer(Container<?>)` method.
- Uses an unbounded wildcard `?` to allow passing a `Container` of any type.
- Prints the stored item regardless of its underlying type.

WHY:
- Demonstrates the flexibility of **wildcards** in generic interfaces.
- Without wildcards, `Container<Object>` is not compatible with `Container<String>` or `Container<Integer>`.
- Wildcards make methods more general and reusable across varying type parameters.

HOW (Logic Flow):
1. Define `printContainer(Container<?>)` that accepts any `Container` regardless of its type parameter.
2. Call `container.get()` safely (result treated as `Object`).
3. Print the contained item to demonstrate compatibility.

BENEFITS:
- Increases **API flexibility** by allowing different generic instantiations to be passed.
- Preserves type safety while avoiding unsafe casts.
- Simplifies utility methods that should operate across multiple type variants.

REAL-WORLD APPLICATIONS:
- Logging or debugging containers without knowing their parameterized type.
- Utility frameworks (collections, serialization, UI rendering) where handling different generic types uniformly is required.
- Example: `List<?>` in the Java Collections Framework is used widely for read-only operations across different list types.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Section24JavaGenerics/src/GenericInterface/Wild Cards

@@ -9,4 +9,4 @@ class WildcardExample {
         System.out.println(container.get());
     }
 }
-Here, the wildcard ? is used, meaning that printContainer can accept a Container of any type.
+Here, the wildcard ? is used, meaning that printContainer can accept a Container of any type.