local function serialize(t, knownTables)
    assert(type(t) == "table", "Table expected got: " .. type(t)) 

    local serialized = ""
    local knownTables = knownTables or {}

    for k, v in pairs(t) do
        local varType, value = type(v)
        if varType == "string" then
            value = string.format("%q", v)
        elseif varType == "number" or varType == "boolean" or varType == "nil" then
            value = tostring(v)
        elseif varType == "table" then
            isRecursive = false
            local t = v
            for k, v in pairs(knownTables) do
                if v == t then
                    isRecursive = true
                    break
                end
            end
            if not isRecursive then
                table.insert(knownTables, v)
                value = serialize(v, knownTables)
            else
                error("Recursive table")
            end
        end
        if value then
            local append = (serialized == "" and "" or ", ") .. (type(k) == "number" and k <= #t and "" or ("[" .. (type(k) == "number" and k or string.format("%q", k)) .. "]") .. " = ")  .. value
            serialized = serialized .. append
        end
    end
    return  "{" .. serialized .. "}"
end