Add ability to restore sequence after differ

tests/test.rs

@@ -102,6 +102,16 @@ fn test_differ_compare() {
     assert_eq!(result, "- one\n?  ^\n+ ore\n?  ^\n- two\n- three\n?  -\n+ tree\n+ emu\n");
 }
 
+#[test]
+fn test_differ_restore() {
+    let first_text = vec!["one\n", "two\n", "three\n"];
+    let second_text = vec!["ore\n", "tree\n", "emu\n"];
+    let differ = Differ::new();
+    let diff = differ.compare(&first_text, &second_text);
+    assert_eq!(first_text, Differ::restore(&diff, 1));
+    assert_eq!(second_text, Differ::restore(&diff, 2));
+}
+
 #[test]
 fn test_unified_diff() {
     let first_text = "one two three four".split(" ").collect::<Vec<&str>>();