anchor.diff:      if (leftIndex >= 0) {
         expect(leftToken, isNotNull);
       }
  -    expect(_incrementalScanner.leftToken, same(leftToken), reason: "Invalid left token");
  +    expect(
  +        _incrementalScanner.leftToken,
  +        same(leftToken),
  +        reason: "Invalid left token");
       if (rightIndex >= 0) {
         expect(rightToken, isNotNull);
       }
  -    expect(_incrementalScanner.rightToken, same(rightToken), reason: "Invalid right token");
  +    expect(
  +        _incrementalScanner.rightToken,
  +        same(rightToken),
  +        reason: "Invalid right token");
     }
   
     /**
  -   * Given a description of the original and modified contents, perform an incremental scan of the
  -   * two pieces of text. Verify that the incremental scan produced the same tokens as those that
  -   * would be produced by a full scan of the new contents.
  +   * Given a description of the original and modified contents, perform an
  +   * incremental scan of the two pieces of text. Verify that the incremental
  +   * scan produced the same tokens as those that would be produced by a full
  +   * scan of the new contents.
      *
  -   * @param prefix the unchanged text before the edit region
  -   * @param removed the text that was removed from the original contents
  -   * @param added the text that was added to the modified contents
  -   * @param suffix the unchanged text after the edit region
  +   * The original content is the concatenation of the [prefix], [removed] and
  +   * [suffix] fragments. The modeified content is the concatenation of the
  +   * [prefix], [added] and [suffix] fragments.
      */
     void _scan(String prefix, String removed, String added, String suffix) {
       //
  
positive.code:     expect(_incrementalScanner.hasNonWhitespaceChange, isTrue);
    }
  
    void test_insert_afterIdentifier1() {
      // "a + b;"
      // "abs + b;"
      _scan("a", "", "bs", " + b;");
  
negative.code:     expect(_incrementalScanner.hasNonWhitespaceChange, isTrue);
    }
  
    void test_insert_convertOneFunctionToTwo_overlap() {
      // "f() {}"
      // "f() {} g() {}"
      _scan("f() {", "", "} g() {", "}");
      _assertTokens(4, 10, ["f", "(", ")", "{", "}", "g", "(", ")", "{", "}"]);
      expect(_incrementalScanner.hasNonWhitespaceChange, isTrue);
    }
  
    void test_insert_end() {
      // "class A {}"
      // "class A {} class B {}"
  