@Test
public void testHeaders() {

  ResourceOptions ro = new ResourceOptions();
  try {
    ro.headers(null);
    fail();
  } catch (Exception ignored) {
  }
  final HashMap<String, Object> headers = Maps.newHashMap();
  headers.put("Foo", "Bar");
  ro.headers(headers).headers();
  headers.put("Baz", "Quux");
  ro.headers(headers).headers();
  ro.header("A", "B");
  final HashMap<String, Object> headers1 = Maps.newHashMap();
  headers1.put("Foo", "Bar");
  headers1.put("Baz", "Quux");
  headers1.put("A", "B");
  assertEquals(headers1, ro.headers());
}