Use this function for commands that both read and write, such as "mapReduce" with an output collection.

Read and write concern and collation can be overridden by various sources. In a transaction, read concern and write concern are prohibited in opts. The highest-priority sources for these options are listed first in the following table. Read preferences are not applied. The write concern is omitted for MongoDB before 3.4.

See the example for transactions and for the "distinct" command with opts.