xxs.js
function dispatch(action, payload) {
    if (process.env.NODE_ENV !== 'production' && dispatching) {
      throw new Error(`'${action.toString()}' was dispatched while '${dispatching.toString()}' was still updating. Updaters should be pure functions and must not dispatch actions.`);
    }
    try {
      dispatching = action;
      state = updater(state, action, payload);
      if (process.env.NODE_ENV !== 'production' && debug) {
        console.info(state);
      }
    } finally {
      dispatching = null;
    }
    updateUI();
  }
function dispatch(action, payload) {
    if (process.env.NODE_ENV !== 'production' && dispatching) {
      throw new Error(`'${action.toString()}' was dispatched while '${dispatching.toString()}' was still updating. Updaters should be pure functions and must not dispatch actions.`);
    }
    try {
      dispatching = action;
      state = updater(state, action, payload);
      if (process.env.NODE_ENV !== 'production' && debug) {
        console.info(state);
      }
    } finally {
      dispatching = null;
    }
    updateUI();
  }
function dispatch ( action , payload ) { if ( process . env . NODE_ENV !== 'production' && dispatching ) { throw new Error ( ` ${ action . toString ( ) } ${ dispatching . toString ( ) } ` ) ; } try { dispatching = action ; state = updater ( state , action , payload ) ; if ( process . env . NODE_ENV !== 'production' && debug ) { console . info ( state ) ; } } finally { dispatching = null ; } updateUI ( ) ; }
dummy spec for the node we're attaching to 
@param {Symbol|string} action? The action to dispatch (or undefined to force a render)
@param {any} payload? Any data associated with the action
@returns {void}
dummy spec for the node we re attaching to