How to fix these errors :

Design and implementing the ordered list program .

2.2) removeFirst() 2 [Hint: Basic Behavior with Add (one element)] (0.0/0.5) 2.2) removeFirst() 2 [Hint: Basic Behavior with Add (one element)] (0.0/0.5) Test Failed! 2.3) removeFirst() 3 [Hint: Basic Behavior with Add tostring() after operation(s) returned wrong value. expected: but was: (multiple elements)] (0.0/0.5) at edu.ser222.m01_03.tests.orderedListTest.assertProperlyEmptyList:70 (OrderedListTest.java) 3.2) removeLast() 2 [Hint: Basic Behavior with Add at edu.ser222.m01_03.tests.orderedListTest.removeFirst2:52 (OrderedListTest.java) (one element)] (0.0/0.5) 3.3) removeFirst() 3 [Hint: Basic Behavior with Add 2.3) removeFirst() 3 [Hint: Basic Behavior with Add (multiple elements)] (0.0/0.5) (multiple elements)] (0.0/0.5) 4.3) remove() 3 [Hint: Basic Behavior with Add (one Test Failed! element)] (0.0/0.5) tostring() after operation(s) returned wrong value. expected: but was: 10.1) toString() 1 [Hint: Empty] (0.0/0.5) at edu.ser222.m01_03.tests.OrderedListTest.assertProperlyEmptyList:70 (OrderedListTest.java) 11.2) iterator() 2 [Hint: Basic Behavior] (0.0/1.0) at edu.ser222.m01_03.tests.orderedListTest.removeFirst 3:90 (OrderedListTest.java) 11.3) iterator() 3 [Hint: Basic Behavior with Generics] (0.0/1.0) 2.4) removeFirst() 4 [Hint: Basic Behavior with Add (multiple elements) + Accessors] (0.5/0.5) 11.4) iterator() 4 [Hint: hasNext Basic Behavior] (0.0/0.5) 11.6) iterator() 6 [Hint: Next Exception] (0.0/0.5) 3.1) removeLast() 1 [Hint: Exception] (0.5/0.5) 11.7) iterator() 7 [Hint: Remove Exception] (0.0/0.5)