nodemcu-firmware/lua_examples/luaOTA/default.lua

--
local function enum(t,log) for k,v in pairs(t)do log(k,v) end end
return {entry = function(msg)
    package.loaded["luaOTA.default"]=nil
    local gc=collectgarbage; gc(); gc()
    if DEBUG then
      for k,v in pairs(_G) do print(k,v)  end
      for k,v in pairs(debug.getregistry()) do print(k,v) end
    end
    gc(); gc()
    print(msg, node.heap())
  end}