Added a more scattered test.

This may be a more realistic representation.

src/test/java/ca/recrown/islandsurvivalcraft/world/generation/UniBiomeIslandGeneratorTest.java

@@ -106,4 +106,30 @@ public class UniBiomeIslandGeneratorTest {
             assertFalse(false, e.getCause().getMessage());
         }
     }
+
+    @Test
+    public void testBiomeGenerationMultithread1608ChunksScattered() {
+        int chunksToDoEach = 268;
+        Runnable g1 = new BiomeGenTask(chunksToDoEach, 0);
+        Runnable g2 = new BiomeGenTask(chunksToDoEach, 2);
+        Runnable g3 = new BiomeGenTask(chunksToDoEach, 4);
+        Runnable g4 = new BiomeGenTask(chunksToDoEach, 6);
+        Runnable g5 = new BiomeGenTask(chunksToDoEach, 8);
+        Runnable g6 = new BiomeGenTask(chunksToDoEach, 10);
+
+        ExecutorService ex = Executors.newFixedThreadPool(6);
+        ex.execute(g1);
+        ex.execute(g2);
+        ex.execute(g3);
+        ex.execute(g4);
+        ex.execute(g5);
+        ex.execute(g6);
+
+        try {
+            ex.shutdown();
+            assertTrue(ex.awaitTermination(1, TimeUnit.MINUTES), "timed out.");
+        } catch (InterruptedException e) {
+            assertFalse(false);
+        }
+    }
 }