(micro)benchmarking Vimscript closures

closures.vim

function Func1(x)
    function! Func1Clos(y) closure
        return a:x + a:y
    endfunction
    return funcref('Func1Clos')
endfunction

function Func2(x)
    return { y -> a:x + y }
endfunction

function Func3(x)
    return funcref('Func3Clos',[a:x])
endfunction

function Func3Clos(x,y)
    return a:x + a:y
endfunction

function TestFunc(f,rounds)
    let i = 0
    let time1 = reltime()
    while l:i < a:rounds
        call a:f(1)(2)    
        let l:i+=1
    endwhile 
    return reltime(l:time1)
endfunction

" test with
" echo reltimestr(TestFunc(funcref('Func3'),100000))