old_contents: // @flow
  import type EntityId from 'types/EntityId';
  import type NormalizedEntity from 'types/NormalizedEntity';
  export type NormalizedEntityDictionary = {
  	[key: EntityId]: NormalizedEntity,
  };
  
new_contents: // @flow
  import type CollectionName from 'types/CollectionName';
  import type EntityId from 'types/EntityId';
  import type NormalizedEntity from 'types/NormalizedEntity';
  export type NormalizedEntityDictionary = {
  	[key: CollectionName]:{
  		[key: EntityId]: NormalizedEntity
  	},
  };
  
subject: fix type