old_contents: export const CHANGE_TYPES = {
    CREATED: 1,
    UPDATED: 2,
    DELETED: 3,
    MOVED: 4,
    COPIED: 5,
  };
  
  export const MESSAGES = {
    FETCH_COLLECTION: 'FETCH_COLLECTION',
    FETCH_MODEL: 'FETCH_MODEL',
    REQUEST_RESPONSE: 'REQUEST_RESPONSE',
  };
  
  export const STATUS = {
    SUCCESS: 'SUCCESS',
    FAILURE: 'FAILURE',
  };
  
  export const APP_ID = 'KolibriStudio';
  
  // Transaction sources
  /**
   * This transaction source will be ignored when tracking the
   * client's changes
   *
   * @type {string}
   */
  export const IGNORED_SOURCE = 'IGNORED_SOURCE';
  
  export const REVERT_SOURCE = 'REVERT/' + IGNORED_SOURCE;
  
  // Tables
  export const CHANGES_TABLE = '__changesForSyncing';
  
  export const TREE_CHANGES_TABLE = '__treeChangesForSyncing';
  
  export const CHANGE_LOCKS_TABLE = '__changeLocks';
  
  export const RELATIVE_TREE_POSITIONS = {
    FIRST_CHILD: 'first-child',
    LAST_CHILD: 'last-child',
    LEFT: 'left',
    RIGHT: 'right',
  };
  
new_contents: export const CHANGE_TYPES = {
    CREATED: 1,
    UPDATED: 2,
    DELETED: 3,
    MOVED: 4,
    COPIED: 5,
    CREATED_RELATION: 6,
    DELETED_RELATION: 7,
  };
  
  export const MESSAGES = {
    FETCH_COLLECTION: 'FETCH_COLLECTION',
    FETCH_MODEL: 'FETCH_MODEL',
    REQUEST_RESPONSE: 'REQUEST_RESPONSE',
  };
  
  export const STATUS = {
    SUCCESS: 'SUCCESS',
    FAILURE: 'FAILURE',
  };
  
  export const APP_ID = 'KolibriStudio';
  
  // Transaction sources
  /**
   * This transaction source will be ignored when tracking the
   * client's changes
   *
   * @type {string}
   */
  export const IGNORED_SOURCE = 'IGNORED_SOURCE';
  
  export const REVERT_SOURCE = 'REVERT/' + IGNORED_SOURCE;
  
  // Tables
  export const CHANGES_TABLE = '__changesForSyncing';
  
  export const TREE_CHANGES_TABLE = '__treeChangesForSyncing';
  
  export const CHANGE_LOCKS_TABLE = '__changeLocks';
  
  export const RELATIVE_TREE_POSITIONS = {
    FIRST_CHILD: 'first-child',
    LAST_CHILD: 'last-child',
    LEFT: 'left',
    RIGHT: 'right',
  };
  
subject: Add frontend constants for relationship changes.