     }
     
     func testChangeMovement() {
-        let a = [PrefixHolder("a"), PrefixHolder("b"), PrefixHolder("c"), PrefixHolder("d")]
-        let b = [PrefixHolder("a"), PrefixHolder("c1"), PrefixHolder("b1"), PrefixHolder("d1")]
+        let a = PrefixHolder.multiple(with: ["a", "b", "c", "d"])
+        let b = PrefixHolder.multiple(with: ["a", "c1", "b1", "d1"])
         
         let diff = Diff(from: a, to: b)
         

        XCTAssert(diff.movements == Set([DiffMatch(1, 2)]))
        XCTAssert(diff.matches == Set([DiffMatch(0, 0), DiffMatch(1, 2), DiffMatch(2, 1)]))
    }
}

    }
    
    func testInsertionDeletionChange() {
        let a = PrefixHolder.multiple(with: ["a", "b", "c"])
        let b = [PrefixHolder("c1"), PrefixHolder("d")]
        
        let diff = Diff(from: a, to: b)
