abstract suspend fun encode(spendingKey: String, pendingTx: PendingTransaction): PendingTransaction
Encode the pending transaction using the given spending key. This is a local operation that produces a raw transaction to submit to lightwalletd.
spendingKey - the spendingKey to use for constructing the transaction.
pendingTx - the transaction information created by initSpend that will be used to
construct a transaction.
Return
the resulting pending transaction whose ID can be used to monitor for changes.