diff --git a/java/src/main/java/io/nayuki/qrcodegen/testQrSegmentAdvanced.java b/java/src/main/java/io/nayuki/qrcodegen/testQrSegmentAdvanced.java
index 8b8e780..75266fa 100644
--- a/java/src/main/java/io/nayuki/qrcodegen/testQrSegmentAdvanced.java
+++ b/java/src/main/java/io/nayuki/qrcodegen/testQrSegmentAdvanced.java
@@ -1,6 +1,8 @@
 package io.nayuki.qrcodegen;
 import static org.junit.Assert.*;
 
+import java.util.EmptyStackException;
+
 import org.junit.Test;
 
 public class testQrSegmentAdvanced {
@@ -14,6 +16,8 @@ public class testQrSegmentAdvanced {
 	private static int min_version = QrCode.MIN_VERSION;
 	private static int max_version = QrCode.MAX_VERSION;
 	
+	private String nullstring = "";
+	
 	/**
 	*Purpose: Testing when user insert over text length
 	*Input: overString, Ecc.LOW, minversion = 1, maxversion = 40
@@ -34,26 +38,37 @@ public class testQrSegmentAdvanced {
 
 	@Test
 	public void is_valid_Test() {
-		assertEquals(QrSegmentAdvanced.is_valid_version(min_version, 1),1);
-		assertEquals(QrSegmentAdvanced.is_valid_version(min_version, 10),1);
-		assertEquals(QrSegmentAdvanced.is_valid_version(min_version, 27),1);
-		assertNotEquals(QrSegmentAdvanced.is_valid_version(min_version, 0),1);
+		assertEquals(QrSegmentAdvanced.is_valid_version(min_version, 1),true);
+		assertEquals(QrSegmentAdvanced.is_valid_version(min_version, 10),true);
+		assertEquals(QrSegmentAdvanced.is_valid_version(min_version, 27),true);
+		assertNotEquals(QrSegmentAdvanced.is_valid_version(min_version, 0),true);
 	}
 
 	/**
 	*Purpose: Using MCDC, Testing version set correctly.
 	*Input: 1, 40, 41, 0, 3, 4
 	*Expected:
-	*	Overrange factor has return 0, So, not equal to 1
+	*	Over range factor has return 0, So, not equal to 1
 	*	Unless it has correct range in version's range, if you insert min_version is bigger that max_version, it return 0;
 	 */
 	
+	@Test
 	public void not_Valid_Version_test() { 
-		assertEquals(QrSegmentAdvanced.not_Valid_Version(1, 40), 1);
-		assertNotEquals(QrSegmentAdvanced.not_Valid_Version(1, 41), 1);
-		assertNotEquals(QrSegmentAdvanced.not_Valid_Version(0, 40), 1);
-		assertNotEquals(QrSegmentAdvanced.not_Valid_Version(5, 4), 1);
+		assertEquals(QrSegmentAdvanced.not_Valid_Version(1, 40), false);
+		assertNotEquals(QrSegmentAdvanced.not_Valid_Version(1, 41), false);
+		assertNotEquals(QrSegmentAdvanced.not_Valid_Version(0, 40), false);
+		assertNotEquals(QrSegmentAdvanced.not_Valid_Version(5, 4), false);
 	}	
-	
-	
+
+	/**
+	*Purpose: This program checking whether its String is empty. SO, i test it working correctly
+	*Input: 1, nullstring, Ecc.Low, 1, 40
+	*Expected:
+	*	occur AssertError
+	 */	
+	@Test(expected = AssertionError.class)
+	public void emptyString_test() {
+		testing.makeSegmentsOptimally(nullstring, Ecc.LOW, 1, 40);
+	}
+
 }