def _update_data(self, data, update_original=False, remove_missing=False):
self._data.update(dict((key, self._deserialize(key, value))<EOL>for key, value in data.items()))<EOL>if remove_missing:<EOL><INDENT>for key in set(self._data.keys()) - set(data.keys()):<EOL><INDENT>self._data[key] = None<EOL><DEDENT><DEDENT>if update_original:<EOL><INDENT>self._original_data = copy.deepcopy(self._data)<EOL><DEDENT>
Low level update of the internal _data dict. Data which are coming as
updates should already be serialized. If update_original is True, the
original_data dict is updated as well.