CacheControlHeaderDelegate implements RuntimeDelegate.HeaderDelegate<CacheControl> { @Override public CacheControl fromString(String header) { throw new UnsupportedOperationException("CacheControl used only for response headers."); }  @Override CacheControl fromString(String header); @Override String toString(CacheControl header);  }
@Test(expected = UnsupportedOperationException.class) public void fromStringIsNotSupported() throws Exception { cacheControlHeaderDelegate.fromString("public"); }