'Pull out the data into dictionary.
Args:
xml_object: xml from file.
system: `system` object.
Returns:
(definition, children) - tuple
definition - dict:
\'answers\': <List of answers>,
\'question\': <Question string>'

@classmethod
def definition_from_xml(cls, xml_object, system):

    if (len(xml_object.xpath(cls._child_tag_name)) == 0):
        raise ValueError("Poll_question    definition    must    include                                                                    at    least    one    'answer'    tag")
    xml_object_copy = deepcopy(xml_object)
    answers = []
    for element_answer in xml_object_copy.findall(cls._child_tag_name):
        answer_id = element_answer.get('id', None)
        if answer_id:
            answers.append({'id': answer_id, 'text': stringify_children(element_answer)})
        xml_object_copy.remove(element_answer)
    definition = {'answers': answers, 'question': stringify_children(xml_object_copy)}
    children = []
    return (definition, children)
