feat(Package): add Test class with null-safe getName demo

What
- Added `Test` class in package `Package`.
- Contains a `main` method that:
  - Calls `getName(2)` to simulate name retrieval.
  - Checks for `null` before using the result.
  - If non-null, prints `name.toUpperCase()` to stdout.
- `getName(int id)` currently returns `null` placeholder (stub).

Why
- Demonstrates a **null-check pattern** before dereferencing method return values.
- Provides a skeleton for later implementing real logic (e.g., fetching a name from a database, map, or API).
- Serves as a small example of defensive coding against `NullPointerException`.

How
- Defined `main` method with program entry point.
- Invoked `getName(2)` and stored in `String name`.
- Added `if (name != null)` guard before calling `name.toUpperCase()`.
- Stubbed `getName(int id)` to always return `null`.

Logic
- **Inputs:** integer `id` (in example, `2`).
- **Outputs:** no output produced since `getName` returns `null`.
- **Flow:**
  1. Call `getName(2)` → returns `null`.
  2. Assign result to `name`.
  3. Run `if (name != null)`. Condition fails (false).
  4. Program terminates silently without printing anything.
- **Edge cases handled:**
  - Prevents `NullPointerException` when `name` is `null`.
  - Safe if `getName` later evolves to return dynamic values (including nulls).
- **Complexity / performance:** trivial; O(1) operations.
- **Concurrency / thread-safety:**
  - No shared mutable state.
  - Safe for multi-threaded invocation.
- **Error handling:**
  - Explicitly avoids runtime error (`NullPointerException`).
  - No exceptions thrown in current stub.

Real-life applications
- Template for testing null-safety in methods that fetch data from external systems.
- Example in tutorials for teaching how to avoid dereferencing nulls.
- Basis for implementing business logic where missing values are valid (and must be checked before use).

Notes
- Current implementation is a stub. Real implementations should replace `return null` with actual logic.
- Alternatives:
  - Return `Optional<String>` from `getName` to force callers to handle absence explicitly.
  - Use `Objects.requireNonNull` if null is unexpected in future designs.
- `toUpperCase()` is locale-sensitive; in production, consider `toUpperCase(Locale.ROOT)` for deterministic results.

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

Author: Someshdiwan

Java 8 Crash Course/Lambda Expression/Optional/src/Package/Test.java

@@ -0,0 +1,14 @@
+package Package;
+
+public class Test {
+    public static void main(String[] args) {
+        String name = getName(2);
+        if(name != null) {
+            System.out.println(name.toUpperCase());
+        }
+    }
+
+    private static String getName(int id) {
+        return null;
+    }
+}