AsyncInvoker.<somemethod>(GenericType<Response>/InvocationCallback<Response>) throws exception when Response.Status != OK.
But javadoc says:
Note that calling the Future.get() method on the returned Future instance may throw
WebApplicationException or one of its subclasses thrown in case the received response status code is not successful and the specified response type is not Response.
But unless <somemethod> has just (Class) argument, the WebApplicationException is thrown anyway.
throws the exception