How do you ensure that a mock object is behaving as expected during testing?

Ensuring that a mock object behaves as expected involves verifying that the methods of the mock object are called with the correct arguments and return the expected values. This can be achieved by using assertions in the test code. Candidates should explain the importance of setting up expectations for method calls and return values and using assertions to validate that these expectations are met during testing. They may also mention the use of testing frameworks like Go's testing package or third-party libraries for mocking, such as "github.com/stretchr/testify/mock."