@Test
    public void testJsonMarshalling_MultiProperty() throws Exception {
        HeaderMap original = new HeaderMap();
        original.add("Header-1", "Value-1");
        original.add("Header-2", "Value-2");
        original.add("Header-3", "Value-3");
        original.add("Header-4", "Value-4");

        ObjectMapper mapper = new ObjectMapper();
        String serializedHeaderMap = mapper.writer().writeValueAsString(original);

        HeaderMap deserializedMap = mapper.reader(HeaderMap.class).readValue(serializedHeaderMap);
        System.out.println(deserializedMap);

        Assert.assertNotNull(deserializedMap.get("Header-1"));
        Assert.assertEquals("Value-1", deserializedMap.get("Header-1"));
        Assert.assertNotNull(deserializedMap.get("Header-2"));
        Assert.assertEquals("Value-2", deserializedMap.get("Header-2"));
        Assert.assertNotNull(deserializedMap.get("Header-3"));
        Assert.assertEquals("Value-3", deserializedMap.get("Header-3"));
        Assert.assertNotNull(deserializedMap.get("Header-4"));
        Assert.assertEquals("Value-4", deserializedMap.get("Header-4"));
    }
Test method for {@link io.apiman.gateway.engine.beans.util.CaseInsensitiveStringMultiMap#toString()}.
gateway/engine/beans/src/test/java/io/apiman/gateway/engine/beans/util/HeaderMapIOTest.java