What is the approach to the libraries used — do all commands use the same mock library or are there no restrictions?

It is recommended to use a single mock library across all project teams. This ensures consistency of tests, simplifies maintenance and onboarding of new employees, and reduces the likelihood of errors due to differences in behavior of various libraries. However, if there are specific requirements in the project, the use of multiple libraries can be considered, but with clear documentation and justification of the choice.