Logger Rate Limiter

Description

Design a logger that decides whether a message should be printed.

A message should print if and only if it has NOT been printed in the
last 10 seconds. Timestamps arrive in non-decreasing order.

Methods:
    __init__()
    shouldPrintMessage(timestamp, message) -> bool
        - True  => print the message (and record this timestamp)
        - False => suppress (don't update the recorded timestamp)

Example:
    log = Logger()
    log.shouldPrintMessage(1,  "foo")  -> True   (first time)
    log.shouldPrintMessage(2,  "bar")  -> True   ("bar" never seen)
    log.shouldPrintMessage(3,  "foo")  -> False  (gap = 2 < 10)
    log.shouldPrintMessage(11, "foo")  -> True   (gap = 10, allowed)
    log.shouldPrintMessage(12, "foo")  -> False  (gap = 1 since t=11)

Edge to watch: when shouldPrint returns False you must NOT update the
stored timestamp. Otherwise repeated suppressed calls would slide the
window forward and never let the message through.

Constraints

- Timestamps arrive in non-decreasing order
- 'Last 10 seconds' means: print only if (timestamp - last_printed) >= 10
- Message strings are arbitrary