[BAEL-3392] Formatted code examples for [BAEL-3392]

java-numbers/src/test/java/com/baeldung/maths/BigIntegerImplUnitTest.java

@@ -0,0 +1,21 @@
+package com.baeldung.maths;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.math.BigInteger;
+
+public class BigIntegerImplUnitTest {
+
+    @Test
+    public void givenBigIntegerNumbers_whenAddedTogether_thenGetExpectedResult() {
+        BigInteger numStarsMilkyWay = new BigInteger("8731409320171337804361260816606476");
+        BigInteger numStarsAndromeda = new BigInteger("5379309320171337804361260816606476");
+
+        BigInteger totalStars = numStarsMilkyWay.add(numStarsAndromeda);
+        BigInteger result = new BigInteger("14110718640342675608722521633212952");
+
+        Assert.assertEquals(result, totalStars);
+    }
+
+}