def append(self, prefix, key, value, cb):
        _log.debug("Append key %s, value %s" % (prefix + key, value))
        # Keep local storage for sets updated until confirmed
        if (prefix + key) in self.localstore_sets:
            # Append value items
            self.localstore_sets[prefix + key]['+'] |= set(value)
            # Don't remove value items any more
            self.localstore_sets[prefix + key]['-'] -= set(value)
        else:
            self.localstore_sets[prefix + key] = {'+': set(value), '-': set([])}

        if self.started:
            coded_value = self.coder.encode(list(self.localstore_sets[prefix + key]['+']))
            self.storage.append(key=prefix + key, value=coded_value,
                                cb=CalvinCB(func=self.append_cb, org_key=key, org_value=value, org_cb=cb))
        else:
            if cb:
                cb(key=key, value=True)
Updates the current configuration.
dataset/ETHPy150Open EricssonResearch/calvin-base/calvin/runtime/north/storage.py/Storage.append--crossover with--dataset/ETHPy150Open UniversalDevicesInc/Polyglot/polyglot/element_manager/api.py/set_config