apollo-client/src/main/java/com/ctrip/framework/apollo/internals/AbstractConfig.java/AbstractConfig/fireConfigChange
class AbstractConfig:  protected void fireConfigChange(String namespace, Map<String, ConfigChange> changes) {
    final Set<String> changedKeys = changes.keySet();
    final List<ConfigChangeListener> listeners = this.findMatchedConfigChangeListeners(changedKeys);

    // notify those listeners
    for (ConfigChangeListener listener : listeners) {
      Set<String> interestedChangedKeys = resolveInterestedChangedKeys(listener, changedKeys);
      InterestedConfigChangeEvent interestedConfigChangeEvent = new InterestedConfigChangeEvent(
          namespace, changes, interestedChangedKeys);
      this.notifyAsync(listener, interestedConfigChangeEvent);
    }
  }