code: function onUpdating(model, attr, options) {
          if (this.relationships) {
              model.changed = _.omit(model.changed, this.relationships);
          }
  
          if (schema.tables[this.tableName].hasOwnProperty('updated_by')) {
              if (!options.importing && !options.migrating) {
                  this.set('updated_by', String(this.contextUser(options)));
              }
          }
  
          if (options && options.context && !options.context.internal && !options.importing) {
              if (schema.tables[this.tableName].hasOwnProperty('created_at')) {
                  if (model.hasDateChanged('created_at', {beforeWrite: true})) {
                      model.set('created_at', this.previous('created_at'));
                  }
              }
  
              if (schema.tables[this.tableName].hasOwnProperty('created_by')) {
                  if (model.hasChanged('created_by')) {
                      model.set('created_by', String(this.previous('created_by')));
                  }
              }
          }
  
          // CASE: do not allow setting only the `updated_at` field, exception: importing
          if (schema.tables[this.tableName].hasOwnProperty('updated_at') && !options.importing) {
              if (options.migrating) {
                  model.set('updated_at', model.previous('updated_at'));
              } else if (Object.keys(model.changed).length === 1 && model.changed.updated_at) {
                  model.set('updated_at', model.previous('updated_at'));
                  delete model.changed.updated_at;
              }
          }
  
          model._changed = _.cloneDeep(model.changed);
  
          return Promise.resolve(this.onValidate(model, attr, options));
      }
docs: Changing resources implies setting these properties on the server side
  - set `updated_by` based on the context
  - ensure `created_at` never changes
  - ensure `created_by` never changes
  - the bookshelf `timestamps` plugin sets `updated_at` automatically
  
  Exceptions:
  - importing data
  - internal context
  - if no context
  
  @deprecated: x_by fields (https://github.com/TryGhost/Ghost/issues/10286)