address comments

src/main/java/net/snowflake/ingest/streaming/OffsetTokenVerificationFunction.java

@@ -7,8 +7,8 @@
 /**
  * Interface to provide a custom offset verification logic. If specified, verification failures will
  * be logged as warnings and reported to Snowflake. This interface could be used when there are
- * certain assumption about the offset token behavior and please reach out to Snowflake if you
- * notice any unexpected behaviors.
+ * certain assumption about the offset token behavior. Please reach out to Snowflake if you notice
+ * any unexpected behaviors.
  *
  * <p>Below is an example that verifies that all offset tokens are monotonically increasing numbers:
  *

src/test/java/net/snowflake/ingest/streaming/internal/StreamingIngestIT.java

@@ -1139,6 +1139,17 @@ public void testInsertRowsWithInvalidStartOffsetToken() throws Exception {
     Assert.fail("Row sequencer not updated before timeout");
   }
 
+  @Test
+  public void testOffsetTokenVerificationFunction() {
+    Assert.assertTrue(offsetTokenVerificationFunction.verify("1", "2", "4", 3));
+    Assert.assertTrue(offsetTokenVerificationFunction.verify(null, "2", "4", 3));
+    Assert.assertTrue(offsetTokenVerificationFunction.verify("1", "2", null, 3));
+    Assert.assertTrue(offsetTokenVerificationFunction.verify("a", "2", "4", 3));
+    Assert.assertFalse(offsetTokenVerificationFunction.verify("1", "3", "4", 3));
+    Assert.assertFalse(offsetTokenVerificationFunction.verify("2", "1", "4", 3));
+    Assert.assertFalse(offsetTokenVerificationFunction.verify("1", "2", "4", 2));
+  }
+
   @Test
   public void testChannelClose() throws Exception {
     OpenChannelRequest request1 =