Handler for dealing with 'value_set' values.

        Unfortunately, CybOX et al. sometimes use comma-separated
        value lists rather than an XML structure that can contain
        several values.

        This handler is called for elements concerning a value-set
        such as the following example::

            <URIObj:Value condition="IsInSet"
            value_set="www.sample1.com/index.html, sample2.com/login.html, dev.sample3.com/index/kb.html"
            datatype="AnyURI"/>

def cybox_valueset_fact_handler(self, enrichment, fact, attr_info, add_fact_kargs):
        """
        Handler for dealing with 'value_set' values.

        Unfortunately, CybOX et al. sometimes use comma-separated
        value lists rather than an XML structure that can contain
        several values.

        This handler is called for elements concerning a value-set
        such as the following example::

            <URIObj:Value condition="IsInSet"
            value_set="www.sample1.com/index.html, sample2.com/login.html, dev.sample3.com/index/kb.html"
            datatype="AnyURI"/>

        """

        value_list = attr_info['value_set'][fact['node_id']].split(",")
        value_list = map(lambda x: x.strip(), value_list)

        add_fact_kargs['values'] = value_list

        return True