The GroupsUpdate API allows for duplicate titles when it should not

[vestrel00]

The Contacts Provider allows multiple groups with the same title (case-sensitive comparison) belonging to the same account to exist. In older versions of Android, the native Contacts app allows the creation of new groups with existing titles. In newer versions, duplicate titles are not allowed. Therefore, this library does not allow for duplicate titles.

Currently, the library's GroupsInsert API follows the behavior of newer versions of Android. Inserting a group with a title that already exists in the same Account will fail. However, using the GroupsUpdate API allows consumers to update the title to an existing title, thereby creating a duplicate.

Later on, the group with the duplicate title gets deleted either automatically by the Contacts Provider or when viewing groups in the native Contacts app. It's not an immediate failure on insert or update. This could lead to bugs!