### Question:
Identifiers { public static Identifier prefixPath(Identifier base, String prefix) { return transformer(base).prefixPath(prefix).apply(); } private  Identifiers(); static Identifier withNamespace(Identifier base, String namespace); static Identifier withPath(Identifier base, String path); static Identifier prefixPath(Identifier base, String prefix); static Identifier suffixPath(Identifier base, String suffix); static Identifier truncatePath(Identifier base, int start); static Identifier truncatePath(Identifier base, int start, int end); static Identifier replacePathSegments(Identifier base, int start, int end, String replacement); static Identifier remove(Identifier base, int start, int end); static IdentifierTransformer transformer(Identifier base);  }### Answer:
@Test void prefixPath() { Identifier base = new Identifier("foo:baz/qux"); assertEquals(new Identifier("foo:bar/baz/qux"), Identifiers.prefixPath(base, "bar")); assertEquals(new Identifier("foo:bar/baz/baz/qux"), Identifiers.prefixPath(base, "bar/baz"), "Multilevel path test failed"); }