updated code to handle duplicate keys

Author: skamble2

src/test/java/com/thealgorithms/datastructures/trees/BTreeTest.java

@@ -1,6 +1,8 @@
 package com.thealgorithms.datastructures.trees;
 
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.ArrayList;
 import java.util.Arrays;