How to clear value set values from node info

Hi,

I have set some values on value set to display on a dropdown in my view. using following method.

l_node_info->set_attribute_value_set( name = 'XYZ' value_set = l_value_set ).

Now i need to clear node info value set. Otherwise particular attribute which i used for dropdown is always showing values added .

Please suggest how to clear value set.

Thanks,

Venkat.