client.waitForTransactionReceipt(txHash) periodically, according to the specified timeout and interval, calls
getTransactionReceipt, until a non-empty response is returned.
client.newBlocksShortPolling()gets all blocks starting
latestby default), then waits for new blocks and gets information about them. It returns
client.newLogsShortPolling()allows to get data on events starting from
fromBlockand subscribes for following contract events.