old_contents: class SaveHandlerStub {
  
    /*
      Saving a document involves two steps.
  
      - syncing files (e.g. images) with a backend
      - storing a snapshot of the document's content (e.g. a XML serialization)
    */
    saveDocument(params) {
      console.info('Simulating save ...', params)
  
      return params.fileManager.sync()
      .then(() => {
        // Here you would run a converter (HTML/XML) usually
        // and send the result to a REST endpoint.
        console.info('Creating document snapshot...')
      })
  
    }
  }
  
  export default SaveHandlerStub
  
new_contents: class SaveHandlerStub {
  
    /*
      Saving a document involves two steps.
  
      - syncing files (e.g. images) with a backend
      - storing a snapshot of the document's content (e.g. a XML serialization)
    */
    saveDocument({fileManager}) {
      console.info('Simulating save ...')
  
      return fileManager.sync()
      .then(() => {
        // Here you would run a converter (HTML/XML) usually
        // and send the result to a REST endpoint.
        console.info('Creating document snapshot...')
      })
  
    }
  }
  
  export default SaveHandlerStub
  
subject: Use explicit params for SaveHandlerStub.