nsMap.addMapping("ns", "xyz");
assertEquals(0, nsMap.getPrefixesBoundToUri("abc", new ArrayList<String>()).size());
// and finally, let's re-bind it
nsMap = nsMap.createChild();
nsMap.addMapping("ns", "abc");
assertEquals(1, nsMap.getPrefixesBoundToUri("abc", null).size());
// and add another similar binding
nsMap.addMapping("ns2", "abc");
assertEquals(2, nsMap.getPrefixesBoundToUri("abc", null).size());