private static Set<Method> allAccessors(BeanInfo beanInfo) {
        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
        Set<Method> accessors = new HashSet<Method>(propertyDescriptors.length * 2);
        for (PropertyDescriptor propertyDescriptor : propertyDescriptors) {
            addNotNull(accessors, propertyDescriptor.getReadMethod());
            addNotNull(accessors, propertyDescriptor.getWriteMethod());
        }
        return accessors;
    }