     let index4 = array.lastIndex(of: 11)
     XCTAssertTrue(index4 == nil)
   }
-
+  
   func testRandom() {
     do {
       let collection = [1]
       for _ in 1...100 {
-      XCTAssertTrue(collection.random() == 1)
+        XCTAssertTrue(collection.random() == 1)
       }
     }
-
+    
     do {
       let collection = [1, 2]
       for _ in 1...100 {

        XCTAssertTrue(collection.contains(value))
      }
    }

    do {
      let collection = ["a", "b", "c", "d", "e", "z", "1", "👻"]
      for _ in 1...100 {

    let index4 = array.firstIndex(of: 11)
    XCTAssertTrue(index4 == nil)
  }
  
  func testLastIndex() {
    // Given
    let array = [1, 1, 1, 2, 3, 4, 4, 5, 8]
    
    // When, Then
    let index1 = array.lastIndex(of: 1)
    XCTAssertTrue(index1 == 2)
