warmUp
Prepares the SDK for a transaction by warming up necessary connections and configurations.
It will establish a new session and fetch configuration if they are not already available. As a best practice, call this method:
When the POS application starts.
When the POS application returns to the foreground.
You do not need to wait for the result before starting a transaction, as the SDK handles the connection state internally.
Return
A Result indicating the outcome. On success, it returns a Result of Unit. On failure, it returns a Result with one of the following exceptions:
TransactionInProgressException: If a transaction is already in progress.
WarmUpInProgressException: If a warm-up is already in progress.
WarmUpFailedException: If the warm-up process failed.