transactionTag property
A tag used for statistics collection about this transaction.
Both request_tag and transaction_tag can be specified for a read or
query that belongs to a transaction. To enable tagging on a transaction,
transaction_tag must be set to the same value for all requests belonging
to the same transaction, including BeginTransaction. If this request
doesn't belong to any transaction, transaction_tag is ignored. Legal
characters for transaction_tag values are all printable characters
(ASCII 32 - 126) and the length of a transaction_tag is limited to 50
characters. Values that exceed this limit are truncated. Any leading
underscore (_) characters are removed from the string.
Implementation
core.String? transactionTag;