def test_inserts(self):
""" Test list inserts.
"""
sll = SinglyLinkedList(Node('first'))
sll.insert_after(sll.first_node, Node('second'))
self.assertEquals(sll.first_node.data, 'first')
self.assertEquals(sll.first_node.next_node.data, 'second')
sll.insert_beginning(Node('before the first'))
self.assertEquals(sll.first_node.data, 'before the first')
self.assertEquals(sll.first_node.next_node.data, 'first')
self.assertEquals(sll.first_node.next_node.next_node.data, 'second')
self.assertEquals(str(sll), 'before the first, first, second')
