### Question:
XPathProvider implements MessageBodyReader<T> { public T readFrom(Class<T> cls, Type type, Annotation[] anns, MediaType mt, MultivaluedMap<String, String> hrs, InputStream is) throws IOException, WebApplicationException { String expression = globalExpression != null ? globalExpression : classExpressions.get(cls.getName()); if (expression == null) { throw ExceptionUtils.toInternalServerErrorException(null, null); } XMLSource source = new XMLSource(is); if (forceDOM) { source.setBuffering(); } return source.getNode(expression, globalNamespaces, cls); }  void setConsumeMediaTypes(List<String> types); List<String> getConsumeMediaTypes(); void setForceDOM(boolean b); void setExpression(String expr); void setClassName(String name); void setExpressions(Map<String, String> expressions); void setNamespaces(Map<String, String> nsMap); boolean isReadable(Class<?> cls, Type genericType, Annotation[] annotations, MediaType mediaType); T readFrom(Class<T> cls, Type type, Annotation[] anns, MediaType mt,
        MultivaluedMap<String, String> hrs, InputStream is);  }### Answer:
@Test public void testReadFrom() throws Exception { String value = "<Book><name>The Book</name><id>2</id></Book>"; XPathProvider<Book> provider = new XPathProvider<>(); provider.setExpression("/Book"); provider.setClassName(Book.class.getName()); provider.setForceDOM(true); Book book = provider.readFrom(Book.class, null, null, null, null, new ByteArrayInputStream(value.getBytes())); assertNotNull(book); assertEquals(2L, book.getId()); assertEquals("The Book", book.getName()); }