The selection criteria of the query.
Select favorite contacts.
For each entry in displayNames, find the first contact whose display name starts with any of the provided display names.
Returns a list of contacts originating from the specified source, or an empty list if none were found.
Group all contacts by contact's first character (it can be a letter, a number, a symbol etc) and contacts count. Used in the scroll bar in order to calculate the recycler view's index.