Create a function `close_compare` that accepts 3 parameters: `a`, `b`, and an optional `margin`. The function should return whether `a` is lower than, close to, or higher than `b`. `a` is "close to" `b` if `margin` is higher than or equal to the difference between `a` and `b`.
When `a` is lower than `b`, return `-1`.
When `a` is higher than `b`, return `1`.
When `a` is close to `b`, return `0`.
If `margin` is not given, treat it as zero.
Example: if `a = 3`, `b = 5` and the `margin = 3`, since `a` and `b` are no more than 3 apart, `close_compare` should return `0`. Otherwise, if instead `margin = 0`, `a` is lower than `b` and `close_compare` should return `-1`.
Assume: `margin >= 0`
Tip: Some languages have a way to make arguments optional.
def close_compare(a, b, margin=0):
    return -1 if b-margin>a else a-margin>b
def close_compare(a, b, margin=0):
    return -1 if b-margin>a else a-margin>b