+/* Causes the original contents of 'column' in 'row_' to be verified as a
+ * prerequisite to completing the transaction. That is, if 'column' in 'row_'
+ * changed (or if 'row_' was deleted) between the time that the IDL originally
+ * read its contents and the time that the transaction commits, then the
+ * transaction aborts and ovsdb_idl_txn_commit() returns TXN_TRY_AGAIN.
+ *
+ * The intention is that, to ensure that no transaction commits based on dirty
+ * reads, an application should call ovsdb_idl_txn_verify() on each data item
+ * read as part of a read-modify-write operation.
+ *
+ * In some cases ovsdb_idl_txn_verify() reduces to a no-op, because the current
+ * value of 'column' is already known:
+ *
+ * - If 'row_' is a row created by the current transaction (returned by
+ * ovsdb_idl_txn_insert()).
+ *
+ * - If 'column' has already been modified (with ovsdb_idl_txn_write())
+ * within the current transaction.
+ *
+ * Because of the latter property, always call ovsdb_idl_txn_verify() *before*
+ * ovsdb_idl_txn_write() for a given read-modify-write.
+ *
+ * A transaction must be in progress.
+ *
+ * Usually this function is used indirectly through one of the "verify"
+ * functions generated by ovsdb-idlc. */