test: updated tests to match the changes of the function in last commit

src/test/java/com/esri/core/geometry/TestGeohash.java

@@ -149,29 +149,20 @@ public void testContainingGeohash2(){
   public void testCoveringGeohashEmptyEnvelope() {
     Envelope2D emptyEnv = new Envelope2D();
     String [] coverage = Geohash.coveringGeohash(emptyEnv);
-    for (int i = 0; i < 4; i++){
-      assertEquals(null, coverage[i]);
-    }
   }
 
   @Test
   public void testCoveringGeohashOneGeohash() {
     Envelope2D env = new Envelope2D(-180, -90, -149, -49);
     String [] coverage = Geohash.coveringGeohash(env);
     assertEquals("0", coverage[0]);
-    for (int i = 1; i < 4; i++){
-      assertEquals(null, coverage[i]);
-    }
   }
 
   @Test
   public void testCoveringGeohashPoint() {
     Envelope2D env = new Envelope2D(180,90,180,90);
     String [] coverage = Geohash.coveringGeohash(env);
-    assertEquals("zzzzzzzzzzzz", coverage[0]);
-    for (int i = 1; i < 4; i++){
-      assertEquals(null, coverage[i]);
-    }
+    assertEquals("zzzzzzzzzzzzzzzzzzzzzzzz", coverage[0]);
   }
 
   @Test
@@ -180,8 +171,6 @@ public void testCoveringGeohashTwoGeohashes() {
     String [] coverage = Geohash.coveringGeohash(env);
     assertEquals("0", coverage[0]);
     assertEquals("2", coverage[1]);
-    assertEquals(null, coverage[2]);
-    assertEquals(null, coverage[3]);
   }
 
   @Test
@@ -191,7 +180,6 @@ public void testCoveringGeohashThreeGeohashes() {
     assertEquals("0", coverage[0]);
     assertEquals("2", coverage[1]);
     assertEquals("8", coverage[2]);
-    assertEquals(null, coverage[3]);
   }
 
   @Test