mergedItem.setEmptySource(item2.toEmptyMap());

        // Sum frequencies
        mergedItem.setQueryFreq(item1.getQueryFreq() + item2.getQueryFreq());
        mergedItem.setDocFreq(item1.getDocFreq() + item2.getDocFreq());

        return mergedItem;
    }

    /**
     * Merges readings at a specific index from two reading arrays.
     */

        SuggestItem item = SuggestItemSerializer.fromSource(source);

        assertNotNull(item);
        assertEquals("test text", item.getText());
        assertEquals(10L, item.getDocFreq());
        assertEquals(5L, item.getQueryFreq());
        assertEquals(1.5f, item.getUserBoost(), 0.001f);
    }

    @Test
    public void testToJson() {
        String[] text = { "json test" };

        SuggestItem item2 = createItem("text", 20L, 15L, 2.0f);

        SuggestItem merged = SuggestItemMerger.merge(item1, item2);

        assertNotNull(merged);
        assertEquals(30L, merged.getDocFreq()); // 10 + 20
        assertEquals(20L, merged.getQueryFreq()); // 5 + 15
        assertEquals(2.0f, merged.getUserBoost(), 0.001f); // max(1.0, 2.0)
    }

    @Test
    public void testMerge_tags() {