CollectionsAssignmentTest.java Line 42 removing item at index instead of Object

[Gloal]

CollectionsAssignmentTest.containsDuplicates:42 IndexOutOfBounds Index 12 out of bounds for length 10

I keep getting the following error because the code at line 42: numbers.remove(12) - tries to remove the value at index 12 instead of the actual object 12. Is this an error with my code or should it be **numbers.remove(Integer.valueOf(12));

[Gloal]

Please ignore - it was answered during class