anchor.diff:          <<"spaceId">> => SpaceId,
           <<"userDetails">> => get_user_details(SessionId, UserId)
       },
  -    json_utils:encode(Body).
  +    json_utils:encode(filter_null_and_undefined_values(Body)).
   
   %%--------------------------------------------------------------------
   %% @private
  
positive.code:         <<"storageId">> => StorageId,
          <<"storageName">> => StorageName
      },
      json_utils:encode(Body);
  get_group_request_body(GroupId, SpaceId, #document{
      key = StorageId,
      value = #storage{name = StorageName}
  
negative.code:         <<"storageId">> => StorageId,
          <<"storageName">> => StorageName
      },
      json_utils:encode(filter_null_and_undefined_values(Body)).
  
  %%--------------------------------------------------------------------
  %% @private
  