setInterval tests:
setInterval without arguments does nothing: undefined
setInterval without interval does nothing: undefined
setInterval with null argument 0 does nothing: undefined
setInterval with undefined argument 0 does nothing: undefined
setInterval with numeric argument 0 does nothing: undefined
setInterval with stringy argument 0 does nothing: undefined
setInterval with boolean argument 0 does nothing: undefined
setInterval with object argument 0 and no argument 1 does nothing: undefined
setInterval with object argument 0 and non-string argument 1 does nothing: undefined
setInterval with object argument 0, string argument 1, and no interval does nothing: undefined
non-numeric interval is treated as 0: 1
non-numeric interval triggered
setInterval forwards rest arguments: 2
function callback called
arg1: arg 1
arg2: 2
object-callback called
arg1: arg 1
arg2: 2
