public final T getFirst() {
        return this.firstNode;
    }
@Test
    public void testGetFirst() {
        assertThat(this.list.getFirst()).as("Empty list should return null on getFirst()").isNull();
        
        this.list.add( this.node1 );
        assertThat(this.node1).as("First node should be node1").isSameAs(this.list.getFirst());
        
        this.list.add( this.node2 );
        assertThat(this.node1).as("List should return node1 on getFirst()").isSameAs(this.list.getFirst());

        this.list.add( this.node3 );
        assertThat(this.node1).as("List should return node1 on getFirst()").isSameAs(this.list.getFirst());
    }