BAEL-1609 Added test for CountingOutputStream

guava/src/test/java/org/baeldung/guava/GuavaCountingOutputStreamTest.java

@@ -0,0 +1,25 @@
+package org.baeldung.guava;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.ByteArrayOutputStream;
+
+import org.junit.Test;
+
+import com.google.common.io.CountingOutputStream;
+
+public class GuavaCountingOutputStreamTest {
+
+    @Test
+    public void givenData_whenWrittenToStream_thenGetCorrectCount() throws Exception {
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        CountingOutputStream cos = new CountingOutputStream(out);
+        
+        byte[] data = new byte[10];
+        
+        cos.write(data);
+        
+        assertEquals(10, cos.getCount());
+        
+    }
+}