As a developer, I want to add a test for changing email in our project to ensure that this feature is working as expected.
The test case covers all relevant scenarios, including verifying that the user can change their email address with a valid authentication token and a new email address.
The test case should verify that the user cannot change their email address without providing a valid authentication token.
The test case should verify that the user cannot change their email address to an already existing email address.
The test case should verify that the user cannot change their email address to an invalid email address.
As a developer, I want to add a test for changing email in our project to ensure that this feature is working as expected.