Call metatable methods inside metatable itself : <p>Is there a way to call metatable methods inside the metatable itself? For example</p>

<pre><code>local t = {}
local mt = {
    __index = {
        dog = function() print("bark") end,
        sound = function() t:dog() end
 }
}

setmetatable(t,mt)

t:Sound()
</code></pre>

<p>raises this error:</p>

<p><em>attempt to call method 'Sound' (a nil value)</em></p>
