RIFT Extending frames

local Frame = nil;
-- let's wrap everything into new scope so it won't pollute the rest of the file
do
    local metatable, methods = nil, { };

    -- "methods" table is our "__index" table with new functions
    methods.Test = function(self)
        print("test");
    end

    -- this is our constructor
    Frame = function(name, parent)
        -- create frame
        local self = UI.CreateFrame("Frame", name, parent);

        -- if this is our first frame created then setup metatable so it contains both new and original functions
        if (metatable == nil) then
            metatable = {
                __index = setmetatable(methods, { __index = getmetatable(self).__index });
            };
        end

        -- alter frames metatable and return it
        return setmetatable(self, metatable);
    end
end