tibia-client/modules/core/dispatcher.lua

local eventId = 0
local eventsTable = { }
local orig = { scheduleEvent = scheduleEvent,
               addEvent = addEvent }

-- fix original scheduleEvent
function scheduleEvent(func, delay)
  eventId = eventId + 1
  local id = eventId
  local function proxyFunc()
      if eventsTable[id] then
        func()
        eventsTable[id] = nil
      end
  end
  eventsTable[id] = proxyFunc
  orig.scheduleEvent(proxyFunc, delay)
  return id
end

function removeEvent(id)
  if id and eventsTable[id] then
    eventsTable[id] = nil
  end
end

-- fix original addEvent
function addEvent(func)
    eventId = eventId + 1
    local id = eventId
    local function proxyFunc()
        if eventsTable[id] then
          func()
          eventsTable[id] = nil
        end
    end
    eventsTable[id] = proxyFunc
    orig.addEvent(proxyFunc)
    return id
end