contextualize_items : contextualize_items contextualize_item
                               | contextualize_item
                               | empty

def p_contextualize_items(self, t):
        """contextualize_items : contextualize_items contextualize_item
                               | contextualize_item
                               | empty"""
        if len(t) == 3:
            t[0] = t[1]
            t[0].append(t[2])
        elif t[1]:
            t[0] = [t[1]]
        else:
            t[0] = []