anchor.diff:            return;
           }
   
  -        final BinaryExpression otherExpression = c;
  +        final BinaryExpression otherExpression = c as BinaryExpression;
   
           final String bcLeftOperand = otherExpression.leftOperand.toString();
           final String bcRightOperand = otherExpression.rightOperand.toString();
  
positive.code:         LinkedHashSet.identity();
  
      if (testingExpression is SimpleIdentifier) {
        SimpleIdentifier identifier = testingExpression;
        bool sameIdentifier(n) =>
            n is SimpleIdentifier && identifier.staticElement == n.staticElement;
        if (negations.any(sameIdentifier)) {
          SimpleIdentifier otherIdentifier = negations.firstWhere(sameIdentifier);
          contradictions
              .add(ContradictoryComparisons(otherIdentifier, identifier));
        }
  
negative.code:   if (_isComparison(node)) {
      comparisons.add(node);
    } else if (_isBooleanOperation(node)) {
      comparisons.addAll(_extractComparisons(node as BinaryExpression));
    }
  }
  
  