Contact

Field	Type	Notes
source_folder_id	BigInteger	Indicate the folder id to which the contact is added to
linked_folder_id	BigInteger	Indicate the folder id of the added contact

Example: You add the folder 1,2,3 to folder 4. The contact table will look as the following:

source_folder_id	linked_folder_id
4	1
4	2
4	3