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. The value of transaction_tag should be the
same for all requests belonging to the same transaction. If this request
doesn't belong to any transaction, transaction_tag will be 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 will be removed from the string.
Implementation
core.String? transactionTag;