opts may be NULL or a BSON document with additional command options:

• writeConcern: Construct a mongoc_write_concern_t and use mongoc_write_concern_append to add the write concern to opts. See the example code for mongoc_client_write_command_with_opts.

• sessionId: First, construct a mongoc_client_session_t with mongoc_client_start_session. You can begin a transaction with mongoc_client_session_start_transaction, optionally with a mongoc_transaction_opt_t that overrides the options inherited from collection, and use mongoc_client_session_append to add the session to opts. See the example code for mongoc_client_session_t.

• validate: Construct a bitwise-or of all desired bson_validate_flags_t. Set to false to skip client-side validation of the provided BSON documents.

• comment: A bson_value_t specifying the comment to attach to this command. The comment will appear in log messages, profiler output, and currentOp output. Requires MongoDB 4.4 or later.

• collation: Configure textual comparisons. See Setting Collation Order, and the MongoDB Manual entry on Collation. Collation requires MongoDB 3.2 or later, otherwise an error is returned.

• hint: A document or string that specifies the index to use to support the query predicate.

• let: A BSON document consisting of any number of parameter names, each followed by definitions of constants in the MQL Aggregate Expression language.