PLACE_HOLDER_NON_EXIST = "__NON_EXIST__"

EVENT_PAIR = "just4vis:pairs"
EVENT_DICT_REMOVE = "dict:remove"
EVENT_DICT_ADD = "dict:add"
EVENT_LIST_REMOVE = "list:remove"
EVENT_LIST_ADD = "list:add"
EVENT_VALUE_CHANGE = "value_changes"
