public void setTimestamp(Long timestamp) {
        this.timestamp = timestamp;
    }
<p>
The epoch time (in milliseconds) when the thing last connected or disconnected. If the thing has been
disconnected for approximately an hour, the time value might be missing.
</p>

@param timestamp
       The epoch time (in milliseconds) when the thing last connected or disconnected. If the thing has been
       disconnected for approximately an hour, the time value might be missing.
aws-java-sdk-iot/src/main/java/com/amazonaws/services/iot/model/ThingConnectivity.java