old_contents: import { PropertyAnnotation } from 'substance'
  
  export default class TestEmphasis extends PropertyAnnotation {
    define () {
      return {
        type: 'emphasis'
      }
    }
  }
  
new_contents: import { PropertyAnnotation } from 'substance'
  
  export default class TestEmphasis extends PropertyAnnotation {
    define () {
      return {
        type: 'emphasis'
      }
    }
  
    static get autoExpandRight () { return true }
  }
  
subject: Fix regression.