anchor.diff:  class ExpressionParserTest_Forest extends FastaParserTestCase
       with ExpressionParserTestMixin {
     @failingTest
  -  void test_1_plus_2() {
  -    Expression expression = parseAdditiveExpression('1 + 2');
  -    expect(expression, isNotNull);
  -    assertNoErrors();
  -    var binaryExpression = expression as BinaryExpression;
  -    expect(binaryExpression.leftOperand, isNotNull);
  -    expect(binaryExpression.operator, isNotNull);
  -    expect(binaryExpression.operator.type, TokenType.PLUS);
  -    expect(binaryExpression.rightOperand, isNotNull);
  -  }
  -
  -  void test_int_literal() {
  -    Expression expression = parseAdditiveExpression('1');
  -    expect(expression, isNotNull);
  -    // assertNoErrors();
  -    expect(expression is IntegerLiteral, isTrue);
  -    IntegerLiteral literal = expression;
  -    expect(literal.value, equals(1));
  -  }
  -
  -  @failingTest
     void test_namedArgument() {
       super.test_namedArgument();
     }
  
positive.code:   }
  
    @failingTest
    void test_parsePrimaryExpression_mapLiteral() {
      super.test_parsePrimaryExpression_mapLiteral();
    }
  
    @failingTest
    void test_parsePrimaryExpression_mapLiteral_typed() {
      super.test_parsePrimaryExpression_mapLiteral_typed();
    }
  
negative.code:   }
  
    @failingTest
    void test_parsePrimaryExpression_parenthesized() {
      super.test_parsePrimaryExpression_parenthesized();
    }
  
    @failingTest
    void test_parsePrimaryExpression_super() {
      super.test_parsePrimaryExpression_super();
    }
  