INSERT_ITEMS_AT(numbers, 1, numbers2)
[1,999,1000,2,3]
INSERT_ITEMS_AT(numbers, 10, numbers2)
[1,2,3,999,1000]
INSERT_ITEMS_AT(numbers, -1, numbers2)
[1,2,999,1000,3]
INSERT_ITEMS_AT(objArr, -10, newItems)
[{"x":4,"y":20},{"x":-1,"y":12},{"x":12,"y":23},{"x":24,"y":33},{"x":37,"y":48}]