def body(self, definitions, body, root):
        """ add the input/output body properties """
        if root is None:
            body.use = 'literal'
            body.namespace = definitions.tns
            body.parts = ()
            return
        parts = root.get('parts')
        if parts is None:
            body.parts = ()
        else:
            body.parts = re.split('[\s,]', parts)
        body.use = root.get('use', default='literal')
        ns = root.get('namespace')
        if ns is None:
            body.namespace = definitions.tns
        else:
            prefix = root.findPrefix(ns, 'b0')
            body.namespace = (prefix, ns)
add the input/output body properties