Date2EpochMilli         Convert a date into an epoch in milliseconds
EpochMilli2Date         Convert an epoch in milliseconds into a date
ThingsboardApi-class    Thingboard API Class
ThingsboardApi_checkToken
                        Check if the token is timeouted and refresh it
                        if necessary
ThingsboardApi_getKeys
                        Fetch data keys for an entity
ThingsboardApi_getTelemetry
                        Fetch telemetry
ThingsboardApi_getToken
                        Get authorisation token from thingsboard server
                        for a specific device
ThingsboardApi_getValues
                        Fetch telemetry
