### Question:
ImmutableNamespaces implements Namespaces { public ImmutableNamespaces withoutPrefix(String... prefixes) { ImmutableNamespaces result=new ImmutableNamespaces(this.map); for(String prefix:prefixes) { result.map.remove(prefix); } return result; } private  ImmutableNamespaces(Map<String,String> map);  ImmutableNamespaces(); ImmutableNamespaces withPrefix(String prefix, String namespaceURI); ImmutableNamespaces withoutPrefix(String... prefixes); @Override Set<String> getDeclaredPrefixes(); @Override String getNamespaceURI(String prefix); @Override String getPrefix(String namespaceURI); @Override List<String> getPrefixes(String namespaceURI); @Override String toString();  }### Answer:
@Test public void testWithoutPrefix() throws Exception { final ImmutableNamespaces ns = this.sut.withoutPrefix(DEFAULT_PR1,DEFAULT_PR2); assertThat(ns,not(sameInstance(this.sut))); assertThat(ns.getDeclaredPrefixes(),hasSize(0)); }