Added a unit test to show the problem

java/src/test/java/gherkin/formatter/FilterFormatterTest.java

@@ -0,0 +1,36 @@
+package gherkin.formatter;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+
+import org.junit.Test;
+
+import gherkin.formatter.model.Examples;
+import gherkin.formatter.model.Tag;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.mock;
+
+public class FilterFormatterTest {
+
+    @Test
+    public void filterFormatterShouldNotClearExampleTags() {
+
+        FilterFormatter filterFormatter =  new FilterFormatter(mock(Formatter.class), Arrays.asList("@filter"));
+
+        final ArrayList<Tag> originalTags = new ArrayList<Tag>();
+        originalTags.add(new Tag("@tag", 0));
+
+        Examples examples1 = new Examples(Collections.EMPTY_LIST, new ArrayList<Tag>(originalTags),
+                "keyword1", "name1", "description1", 0, "id1", Collections.EMPTY_LIST);
+        Examples examples2 = new Examples(Collections.EMPTY_LIST, new ArrayList<Tag>(originalTags),
+                "keyword2", "name2", "description2", 0, "id2", Collections.EMPTY_LIST);
+
+        filterFormatter.examples(examples1);
+        filterFormatter.examples(examples2);
+
+        assertEquals("Example tags should not be modified", originalTags, examples1.getTags());
+        assertEquals("Example tags should not be modified", originalTags, examples2.getTags());
+    }
+}