def load(self):
        if os.path.exists(self.path):
            with open(self.path, 'r') as f:
                self.body_labels = collections.OrderedDict(json.load(f))
def get(self, key, default=None):
        try:
            value = self[key]
        except KeyError:
            value = self._to_python(default)
        return value