What's wrong with Buffer class in Luvit?

[Dmitri Voronianski]

I'm searching a way to detect Buffer in Luvit. However this code is not working:

local instanceof = require('core').instanceof

local Buffer = require('buffer').Buffer

local b = Buffer:new('chunk')

p(b)
-- { ctype = cdata<unsigned char *>: 0x7feda4701bc0, length = 5 }

p(instanceof(b, Buffer))
-- false (WTF?)

Core's instanceof method (https://luvit.io/api/core.html#core_core_instanceof_obj_class) returns `false` where it should be true obviously.