var obj1 = {
5: [
{title: 'test 1', props: [4,5]},
{title: 'test 2', props: [1,2,5]},
],
2: [
{title: 'test 3', props: [2,4]},
],
...
}
var arr2 = [
['5', [
{title: 'test 1', props: [4,5]},
{title: 'test 2', props: [1,2,5]}
]],
['2', [
{title: 'test 3', props: [2,4]}
]],
...
]