     // ======================================================= //
     
     func testIndexBasedSubscriptForRetrievingValues() {
-        let elementAtIndex0 = self.orderedDictionary[0]
+        let elementAtIndex0 = orderedDictionary[0]
         XCTAssertEqual(elementAtIndex0.0, "A")
         XCTAssertEqual(elementAtIndex0.1, 1)
         
-        let elementAtIndex1 = self.orderedDictionary[1]
+        let elementAtIndex1 = orderedDictionary[1]
         XCTAssertEqual(elementAtIndex1.0, "B")
         XCTAssertEqual(elementAtIndex1.1, 2)
         
-        let elementAtIndex2 = self.orderedDictionary[2]
+        let elementAtIndex2 = orderedDictionary[2]
         XCTAssertEqual(elementAtIndex2.0, "C")
         XCTAssertEqual(elementAtIndex2.1, 3)
     }
     
     func testIndexBasedSubscriptForSettingValues() {
-        self.orderedDictionary[0] = ("F", 10)
-        self.orderedDictionary[1] = ("B", 5)
-        
-        let elementAtIndex0 = self.orderedDictionary[0]
+        orderedDictionary[0] = ("F", 10)
+        orderedDictionary[1] = ("B", 5)
+        
+        let elementAtIndex0 = orderedDictionary[0]
         XCTAssertEqual(elementAtIndex0.0, "F")
         XCTAssertEqual(elementAtIndex0.1, 10)
         
-        let elementAtIndex1 = self.orderedDictionary[1]
+        let elementAtIndex1 = orderedDictionary[1]
         XCTAssertEqual(elementAtIndex1.0, "B")
         XCTAssertEqual(elementAtIndex1.1, 5)
         
-        let elementAtIndex2 = self.orderedDictionary[2]
+        let elementAtIndex2 = orderedDictionary[2]
         XCTAssertEqual(elementAtIndex2.0, "C")
         XCTAssertEqual(elementAtIndex2.1, 3)
     }
     
     func testRetrievingElementAtNonExistentIndex() {
-        XCTAssertNil(self.orderedDictionary.elementAtIndex(10))
+        XCTAssertNil(orderedDictionary.elementAtIndex(10))
     }
     
     func testIndexBasedInsertionsOfElementsWithDistinctKeys() {
-        self.orderedDictionary.insertElement(("T", 15), atIndex: 0)
-        self.orderedDictionary.insertElement(("U", 16), atIndex: 2)
-        self.orderedDictionary.insertElement(("V", 17), atIndex: 5)
-        self.orderedDictionary.insertElement(("W", 18), atIndex: 2)
+        orderedDictionary.insertElement(("T", 15), atIndex: 0)
+        orderedDictionary.insertElement(("U", 16), atIndex: 2)
+        orderedDictionary.insertElement(("V", 17), atIndex: 5)
+        orderedDictionary.insertElement(("W", 18), atIndex: 2)
         
         let XCTAssertEqualedOrderedDictionary: OrderedDictionary<String, Int> = [
             ("T", 15),

            ("B", 5)
        ]
        
        XCTAssertEqual(self.orderedDictionary.count, 3)
        XCTAssertTrue(self.orderedDictionary == expectedOrderedDictionary)
        XCTAssertEqual(previousValue, 2)
    }
    

            ("C", 3)
        ]
        
        XCTAssertEqual(orderedDictionary.count, 3)
        XCTAssertTrue(orderedDictionary == expectedOrderedDictionary)
        XCTAssertEqual(previousValue, 2)
    }
    
    func testIndexBasedInsertionOfElementWithSameKeyAtItsCurrentIndex() {
        let previousValue = orderedDictionary.insertElement(("B", 5), atIndex: 1)
        
        let expectedOrderedDictionary: OrderedDictionary<String, Int> = [
            ("A", 1),
