@Theory
    public void shouldGenerateSensibleToString(int size) throws Exception {
        CaseInsensitiveStringMultiMap actual = new CaseInsensitiveStringMultiMap(size);
        actual.add("a", "b").add("c", "d").add("a", "x");
        Assert.assertEquals("{a => [b, x], c => [d]}", actual.toString());
    }
@author Marc Savy {@literal <msavy@redhat.com>}
gateway/engine/beans/src/test/java/io/apiman/gateway/engine/beans/util/CaseInsensitiveStringMultiMapTest.java