Add a test to verify that the function removes duplicated context values from a list.

Move the equals comparison in a separate class to be reusable.

Filter duplicate list entries by using the value comparator. The equals() for list and context values doesn't work properly because of the nested structure.

Add a test to verify that the function removes duplicated context values.

Remove duplicated context entries from the concatenated list.

Add a test to verify that the function returns duplicated context values.

Return duplicated context entries from list.