“optional part”可以造什么句，optional part造句

Again, the return messages are an optional part of a sequence diagram.

If you decide later to add more optional parts, download the additional optional parts and rerun the extraction tool prior to attempting the installation.

Some pair programmers regard rotation as an optional part of the practice, and on a small team, or with few programmers willing to pair, there might be little alternative.

The service provider catalog is an optional part of the service discovery process.